I don't know how it will be with this particular mod. As
SonsOLiberty says, it may be that when you get to the post 1.15.1a content you will find some errors. In other cases I have seen that the game continues without errors but obviously without the help of the mod in the new content.
In any case, the game has so much content that you may be able to play it for a few days without being affected by the mod being outdated.
If I were you I would play during these days and install the new mod over the old one when it comes out. Your saved game will not be affected.