You don't have took to the America. Dakar does the same already. Anyone can build car there with variety of engines. And there are a lot of entries from various makers, privateers, or tuners.
For example, Martin Prokop is building his Ford Raptor in his team. Well if a privateers can build Dakar car, I'm sure that huge teams like Prodrive, GCK or Oreca will be able to build Rally1 car.
Since Rally1 cars are not proper rally cars those organisations you mention can do this already (if they can fund it and find a manufacturer to stick their badge and headlights on it)
Idk how much reliable is Google translate, but
"We are working on the project to prepare for WRC 27, a development step that interests us"
doesn't sound like they are talking about next season....
1 Solberg 2 Ogier 3 Evans 4 Katsuta 5 Fourmaux 6 Pajari 7 Neuville 8 Sordo dupanton
[WRC Pickems 2026) R6 - Rally de...