So I had a discussion about the Dimensional Vortex with someone in Discord recently, and I came to a rather cool revelation for a new theory. As we know, there are multiple dimensions in the CT multiverse that follow their own sequence of events based on possibilities. It is basically the many worlds theory where every possible outcome has its own reality. Some are very similar, like Chrono Cross and Radical Dreamers. Others are very different, like the Dinopolis timeline. But they are all following their own sequence of events from the beginning of time.
Before we get into this, I am not claiming several splits to a single timeline. Inter-dimensional travel is still possible in the DS version of Chrono Trigger and even in Chrono Cross as seen by Dinopolis being in the Time Crash incident. The only timeline that we know of that splits off from a singular dimension is Home World in Chrono Cross, which split from another world. The Chrono Cross timeline (and I am stealing this analogy) is basically a fork where one single dimension splits into two separate timelines at a certain point. All other known timelines are their own dimensions that follow events either very closely, or very differently based on what alternate possibility is taking place. This is confirmed by Magus within the Dimensional Vortex of CT DS.
Now to the theory at hand...
Basically there are three different versions of CT. The SNES version, the Playstation version, and the DS version. Yes I know there is a mobile and steam version as well, but they are basically just ports of the DS version with no difference between them outside of how they perform. So for this theory, I will only be refering to the three.
In this theory, SNES version of CT is its own timeline outside of Chrono Cross. You play through the game, the end. No Fall of Guardia, no disappearance of the masamune, and no FATE creating El Nido. This makes sense because there is nothing leading into Cross, as Cross was not being planned at the time. But there is still that one story arc that was left unresolved between Schala and Magus that led to Cross being made in the first place...
And Kato addressed that with the next entry in the SNES timeline. Radical Dreamers would be the true direct follow up to this version of CT (sorry Lucca, you don't get off that easy). Here Schala IS Kid reincarnated, rather than just being a "daughter clone". She does not become the Time Devourer, but her story does continue. The Radical Dreamers timeline is confirmed to exist in Cross itself, and seeing how RD was eventually formed into a CT follow up, this makes sense as there are no references that tie the SNES version of CT to CC found within the game itself. As a bonus, if you look at "out of world evidence" RD was released only in Japan via an add on service to the SNES. So essentially the SNES timeline is actually contained on the SNES itself. Probably a coincidence, but it is still a neat bit to point out.
Then we have the Playstation timeline, where Chrono Cross takes place. The PS version of CT, unlike the SNES version, actually had content added to the game that ties it to Cross. In this timeline, the Fall of Guardia takes place via Dalton's revenge, which lead to the disappearance of the Masamune, and to Porre being a military nation. FATE creates El Nido after the Time Crash and the events of Chrono Cross take place leading to a split in the PS timeline we know as Home World and Another World. The where abouts of Crono and Marle are unknown in this timeline as well, outside of speculation. As an added bonus, both games are tied to the Playstation console.
Now we have the DS version, which is a little more complicated. Outside of a more accurate translation, the battle arena, and the ability to peak into the Dinopolis Timeline via the Lost Sanctum...it is basically the exact same timeline as the Playstation Timeline. The mentioned additional content has no effect on that.
There is one bit however, that does create a DS timeline, that is left wide open with no known follow up. AFTER you kill Lavos and you are greeted with the ending scenes from the PS version, something happens. A Dimensional Vortext opens up in ANOTHER TIMELINE right before Crono would have fought and killed Lavos. The Dimensional Vortex is confirmed to be canon, but requires you to beat the game and reload your save from just before that. It makes sense that killing Lavos would trigger such an event in another dimension, as this would lead our heros to find the Dream Devourer. Here they encounter Dalton and learn of his plan. They also run into Magus from the Playstation timeline, as he states that he comes from a future where he and the group already killed Lavos. This implies that he is from the timeline where you just killed Lavos and beat the game and that the party you are controlling is from an alternate timeline where a Dimensional Vortex opens, triggered by the fall of Lavos. He also states that there are as many worlds as there are potentialities, confirming the many worlds theory.
You see him fight and fail, then it is revealed that this Magus is sent back to his timeline, where he erases his memory to POTENTIALLY become Guile in Chrono Cross. The party you controlled however is sent back to the other timeline, from which they entered the Dimensional Vortex. They now have knowledge of the Dream Devourer in this timeline, as well as Dalton's plan to attack Guardia. What they do with said info is anyone's guess however, as the DS timeline (only the part pertaining to the Dimensional Vortex) is left wide open with no follow up.
So what does all of this mean exactly?
Well I think that this was Kato making a statement. He knows there will likely never be a Chrono 3...but that does not mean the IP is dead. With the Dimensional Vortex, every relevant fanfic, fangame (Example Crimson Echos and Flames of Eternity), etc is made canon to their own Dimensional Timeline that follow their own sequence of events in the Chrono Multiverse. Basically SE did not greenlight him to make a sequel in his vision after Cross. But the Chrono franchise continues to live through the minds and hearts of the fans. There are as many worlds as there are potentialities, and we have been entrusted by the man himself to keep these worlds alive.