Give it a few years. Maybe announce the developer, then go silent for years (not two decades though) while they work on it quietly. Don’t hype it up, don’t ask the devs for press updates. Let the massive success of BG3 fade a little from recent memory so the new developers can do their own thing with it without having to deal with the pressure of following BG3.

The worst thing they could do is push for BG4 too quickly.