Fincher’s connection to the show is pretty noticeable in almost every aspect of it in my opinion. I would much rather wait until he’s free and interested than lose that influence completely. Also interestingly, looking up info about the showrunners led me to a quote from a while ago that makes me think the five season plan hasn’t been the case for a long time, maybe not since Fincher took over the full duties for S1 and reworked some things. I’ll have to dig and see which articles about that are more recent. At this point I certainly do not have my hopes set on that much content ever happening.