In light of that, it seems reasonable for the developer to expect advance warning at least in the form of a press release prior to the update being made available.
The modder said it themselves. It will take time for them to check the 4 years of work to see if it still function. At this point, no matter when Bethesda drop the update, they will complaint that it break their mod. This has been going on since the launch of FO4 where every time bethesda update the game, it break the mod, people complain about it, some straight out announce they won't fix it until the final update. It's nothing new.
They did...
The modder said it themselves. It will take time for them to check the 4 years of work to see if it still function. At this point, no matter when Bethesda drop the update, they will complaint that it break their mod. This has been going on since the launch of FO4 where every time bethesda update the game, it break the mod, people complain about it, some straight out announce they won't fix it until the final update. It's nothing new.