Well, you can't export to PS4 on Unity without buying (suscription) and get a license, and keep paying suscription while you update your licensed game (the right Publisher can help with all this), for XBox uses UWP I think, like Godot, Switch export seems to be restricted by who-knows-what.
In the case of Unreal, they offer the source to export on consoles to certified devs for free, more or less like some Godot devs do when certified devs appear.
Yes, a Godot game was (ex)ported to PS4.
Since UWP is available, means XBox too.
I think 3.1 will get VR stuff to make life easier on that, some people is already working on features.