I can't help but feel like this situation is more complicated...
The creator in question wasn't the sole creator of this whole comic, just the writer. The art was by Scarlozet and a studio called Kisai Entertainment. So I assume they either pitched the project to Tapas to be a Tapas Original... or even just applied to be a writer on the Originals program and were assigned to this title? (Can't find any info).
If you pitch a story to be a title for a big publisher like Tapas, Marvel, DC... you don't own it. That's pretty standard. The company owns it. It sucks, yeah, but it's really normal, and I don't know why this writer didn't read the contract before signing it. I don't get royalties off the books I work on as part of a team at my day job, and if I leave my dayjob, I won't have the rights to the books I worked on with them, or even any ideas I came up with for their books, and won't get royalties, because they were made as part of a team under a contract I knowingly signed that puts the ownership of everything I do at that company under my boss and her company. The creator of The Vampire Diaries, similarly doesn't own the rights, or any right to get revenue from that series after having been replaced as the writer, and doesn't get revenue from the TV series either... that's the sad reality of contracts like this.
If you don't want a corporation to own your IP... don't sign onto a contract where you're making an IP for a corporation that'll own your IP. You can't sign a contract like that and then just hope they'll be nice and give you the royalties anyway. Companies aren't nice. They're not your friends. No matter how friendly they are, or how you might have a rapport with some of the staff working for them.
I dunno... I don't know how much the creator earned from the contract, like was there a salary, or an advance? Was the revenue share the only income made? If it really was an unfair scenario, I do feel bad for the writer... but we all surely remember that Bayonetta fiasco a couple of months ago, where the actor made it sound like the contract was a lot more unfair by leaving out and distorting details, so now I'm wary of just immediately trusting posts like this.
The post mentions other creators who have had similar things happen. Have any of them come forward?