Cavalary: Heh, the "joys" of DRM-ed platforms in that tweet, if on Steam or Epic, please consider finishing your game before Feb 28 because after that the old version will be removed and your saves won't work with the new one.
amok: *shrug* if the game was on gOg - the old versions save files would still not work with the new version. this has nothing to do with platform or drm vs drm-free.
On the other hand, with the (hypothetical) GOG version, you would not be forced to update the game on that date. You could just continue playing the old version, and keep the offline installer around in case you need to re-install a version that can load your old save.
(Of course, you wouldn't get access to the new features or DLC unless you install the new version, but at least you'll have that choice, which means you can take as long as you need to to complete the previous playthrough, and then install the new version when you are done with the old save.)