I don't understand the thinking of doing a sequel years , no decades later.

Yea I'm looking at you Ghostbusters 3

That was my immediate thought as well. It's called striking while the iron is hot. The Studios seem to forget about who their audience is going to be when either....or both movies are released. These new movies will be targeting a young crowd, one that most likely has never seen or heard of the first films. And as far as the older audience is concerned, most will probably not care, thus dwindling an already small fan base. Now you have already lost revenue before shooting a single frame of film thus ensuring a smaller opening box office return,