First of all, let me preface by saying I should put "new" in quotation marks here. I've been around since before 2008, and in that time never heard anyone put this theory forward, so I'm guessing I'm the first. Anyhoo...
Schala could have easily escaped the Ocean Palace, she just chose [not to. After certain events, she tells the party that she only has enough power left in her pendant to teleport the three of them to safety, but not herself.
That... ...is kind of BS. :/ Ok but hear me out here:
The party is able to use the Mammon Machine to power up their version of the pendant, and when Schala saves the party, they are literally
sitting right in front of it. Given materials in both CTDS's new ending and both sequels, it can be reasonably presumed that Schala had no intention of leaving the Ocean Palace, especially not if her salvation came from the accursed Mammon Machine.
Hating what she'd done, refusing what she said or heard, to simply continue living was her curse.
tldr; Theoretically, Schala could have escaped and even avoided ending up in the DBT by way of recharging her pendant.
She just didn't want to, for the pain was too great.