I dont know if we're on the same page here. It isn't a question of engineering time. It's a legal problem. It's not going to become feasible in the way ordinary problems do.
There's a couple companies out there that will port your game to consoles for you. [1]
The issue here is that Godot isn't someone you can contact to support their systems. It's an open source project. They either add it to the source, which they can't because of NDAs, or they point you to companies who have a track record of porting and publishing Godot games on Switch, PS4 and Xbox One, which they are currently doing:
It's feasible that they could do the work themselves and only allow access to a branch or patches for console to folks who have signed the NDA. This is basically how Epic works with Unreal. The Unreal source code is available for anyone to look at on github, but it doesn't include any console-specific code.
Open source projects can definitely be contacted in most cases (including Godot) and anybody can fork the project to support a given console. Vendors can publish such support under NDA.
There's a couple companies out there that will port your game to consoles for you. [1]
(1): http://www.lonewolftechnology.com/