The rgp is dead in the water. They dumped the rifles to EuroOptic. They are pretty awesome but the parts availability is pretty much non existent.
As far as the Acr, the remdef Acr is it’s own thing. It’s pretty much in the same boat as the rgp. Maybe a step above it.
If they were to release a remdef Acr now, it would most likely be identical to one of mine with a new lower and maybe a fixed adjustable stock (if needed). The brand new acrs actually are further developed than the defense acrs. I don’t think they would release them with the Remington mounting system since everyone went to mlok.