Our version numbering scheme is season.episode.bugfix, hence the first public release for the latest episode is v2.5.0.
Yes, v2.1.0 was released on Christmas 2023 for top tier patrons. But why are you talking about it?
If you have a normal save from v1.9.x (after MC left Dani's house after their date ended), you can use it to start S2 in any v2.x. But, we don't use export saves that were a part of v1.9.0. I recommend using v1.9.1 to create all your playthrough saves for S2.