From my understanding, any saves you make, up to and including this latest update will not work with the NEXT update.
You can probably play this update with old saves, but it's the *NEXT* update that will make all your saves effed.
Hence I see zero reason, personally, to play this update.
For me this is just curtain down, cant be bothered replaying this game again.
Dunno why he couldn't do this thing once the game is completed instead. Dev himself, has stated that the finale of the story is before the end of the year, or January at the latest. In other words, game is almost complete, and NOW, on the finish line, he forces people that put time into the 'game' to replay the entire thing again?