Potter fans are mixed (at best) on the franchise. The biggest Potter fan I know, absolutely HATES CoG. The general public is indifferent towards it (at best.)
A “billion dollar franchise” means less and less when each Disney film clears a billion easily.
I can’t even imagine the confusion of a Potter fan or average guest being confronted with a random Paris land at the new park. There is zero attachment or familiarity to it. Shoot, MACUSA would at least make sense with possible Ilvermorny merch opportunities. But I think WB/JKR got burned bad with the appropriation indictments.
And then there’s Johnny Depp.
Safe and logical bet is to build the London Ministry, a work of art by Stuart Craig, which bridges the gap of both franchises. It will be beloved by Potter fans and familiar to average guests.
I just don’t see how you dump a cool billion into an entire land based on horribly received movie. Maybe it was the plan a few years ago, but I cannot see how this hasn’t changed since. As has been pointed out, Warner Bros is aware there is a problem and has delayed the films accordingly. If it were anyone but JKR, the franchise would be DEAD.