Hell no.

The purpose of consoles is exactly the opposite... Everybody gets the SAME specs, developers and gamers can all expect it. Having some up-gradable component that can affect the performance of the game is defeating this purpose.

The reason the consoles get better performance for the same theoretical power as a PC is because they only have one thing to optimize for. If you start throwing in variables, it will only cause problems, or it will make no difference because makers will only develop for the weakest base model. Upgrading your RAM makes no sense in consoles.

Consoles let alone current gen have absolutely no chance of doing 4k 30fps at all, I'm seeing some high end rigs trying to get 4-8k 60fps and even they are struggling. 4k just isn't all there yet but 2k definitely is.

I would say No. Because that would create a split userbase.