In a dream case we would have Skoda, Toyota, Hyundai, Msport, Proton and Citroen all with a 2 R5s going for a WRC2pro title with young drivers. Then it would actually make sense. But that's not going to happen in WRC.

If they want to split R5 make it like ERC u28 is in ERC. Everyone fights for the same title under the same rules, but then there is change for youngsters (privateers in WRC case) to fight a trophy for their own.

We have a good number of R5 drivers in the (most of the) events but not that many that we need to split them into Pro's and privateer's.

Is the WRC2pro win really a "accomplishment" for Kalle or Gus in Monte when there is just 2 drivers? well no.
Is the WRC2 win for someone (for example Huttunen, who is not a newbie) in Finland really a win when if there is 6 R5 drivers faster than him in the "pro" category, I would bet, No.
Yes, they maybe a factory drivers or most likely just entried by one but still driving in the equal machines.