Don't you think it's a bit strange that you won't watch BR because you're afraid it will change your perception of 2049, but you want a game studio committed to "controversial" storytelling decisions that "you are not ready for" to pick up where the movie left off? Sequels can and have retroactively tarnished great original stories--ask anyone who's seen the Matrix "trilogy" or read all the Bernard Samson spy novels by Len Deighton (trust me, stop after one).
As for the movies [Unpopular Opinion Warning] having watched both Blade Runners--the first several times thanks to fanboy friends--I'd say go ahead and sit through the director's cut. It will give 2049 some extra layers, but it won't damage your perceptions of the movie in any way. In fact, it will probably only make you appreciate it more by comparison.
Keep your expectations low though, and probably have some caffeine handy to keep you awake. It's a revered sci-fi classic with an interesting visual design, but its ability to shock and amaze or mess with your mind must have been eaten up by imitators a long time ago. For me, it is just a slog to sit through. I disliked it so much (multiple times) that I straight up refused to watch 2049 for years in spite of all the recommendations.
EDIT: "hated" was a bit strong