I just dug into the details. Yes, it looks pretty legitimate: copyright remains held by the individual contributors without a Contributor License Agreement, they are sponsored by a true non-profit foundation with robust non-profit policies and suitably non-profit legal status in the Netherlands, their money and important assets like the Godot trademark itself are held by a mixture of that non-profit foundation and (possibly as a transitional matter) the longstanding free software non-profit charity in the US which was their primary legal home for 7 years.

I was formerly heavily involved in the leadership of the other major US non-profit charity that does this kind of fiscal sponsorship (and which maintained a friendly and collaborative relationship with the charity that Godot previously used). They’re not scamming you in the way of a lot of executives at VC-funded for-profit startups (and their acquirers) when they make entirely legally unenforceable statements about what will or won’t happen in the future which they don’t necessarily even believe themselves.