Truly, people won't care about the new team as long as they're lovable, identifiable characters like the originals were in the first film. Of course there will be the lot that is ded-set against accepting a new team no matter what, but that's their problem.
Ghostbusting as an idea is bigger than Murray, Aykroyd, Ramis and Hudson. It's such a great concept that it's enjoyable no matter who's doing it! Now, since the original team will be in the film, I want them to be the main focus, but shifting to a new team = just fine, if they're great characters. I mean, who didn't like the Denver Ghostbusters in Braxtan's movies? Nobody complained because they're just supposed to be another franchise? I'm sorry, that proves that any team of Ghostbusters can be loved by an audience if the audience is willing to accept them.
Extreme Ghostbusters failed out-of-the-gate because the characters were hollow cliches at first. But by about the midpoint of the show, the team got more fleshed out and was better written. Truly; Roland, Garrett (dumb handicap aside), Eduardo and Kylie truly came into their own later in the show.