If Soviet troops keep the lid on and a modicum of border security is maintained, does a Berlin Wall demolished on CCCP command really have the same effect on the Germanies as one torn down by the masses as guards stand by confused? I don't think so.
That would look to Reagan and company an awful lot like an outright Soviet "victory" in Europe. It might well be the best thing for Europe, but bear in mind that German troops ARE the conventional NATO forces, and any prospect of winning a ground war goes out the window with such a move. Beyond that, given the history of East Germany what is going to make the west anything like willing to declare neutrality? Honestly giving up East Germany in exchange for getting (once again) acceptance of continued control of Poland might be the best bet here.