Basically they were half arsing development to milk Patreon but you can't keep that up indefinitely and this game had been on Patreon since Patreon launched (2016). Time was running out and in order to keep that steady revenue coming in, whilst minimizing the actual work required, they decided changing to a live service model was the best solution.
The plan seems to have been to launch a F2P then every 3 months or so add a character model and animation set and boom, you've got a game you can milk for an extra few years getting $x every quarter. If you've got a good framework for your game, development of which was kindly funded by Patreon no less, this is a pretty profitable solution.
Issue is they massively misjudged both the demand for a multiplayer porn game and their ability to execute it. What we have as a result is a game that once upon a time had ~1.5k players logging in when it dropped on Steam now struggling to hit 200 players weeks after the first update in 14 months:
The funny thing is that in this time they could probably have wrapped up development of Fallen Doll (under the build they now call Origins), sold it on Steam to a wider market for tens of thousands of sales at ~$20 and then
gone back to Patreon to develop Paralogue.
Instead they've done another few "rebuilds" and all they have to show for it is a game that has precisely zero hope of ever maintaining the kind of player count or conversion rates you need for a F2P to be profitable. It is one of the most spectacularly mismanaged projects I have ever seen. Really funny to watch though.