Actually, they said that a long time ago.
SI and Steam stated that when you update the game via steam (and this year steam is the only way to do that), you must always update with the last version available.
So i would think that would be very clear to everyone that, when you update the game, there is no way to go back.
What you may argue is, the old system was better. Last year we could apply a patch, test it, and if we didn't like it, we could uninstall the game, and install it again with the patch that we choose. (for example last year there were 3 patches, but many people decided that patch 11.2 after testing patch 11.3)
This year we dont have this choice, because SI... the owner of the game... decided like this! It's their right!