I delegate 40k CP to one of my alt accounts, that plays in silver. It's mostly Bronze with a lot of GF. I don't think there should be a need to have a whole set to be able to participate.

Also one thing that came to my mind: You can't just say this change won't affect new players, because atm even Alpha/Beta Cards are quite affordable. I'm mostly talking about Commons and Rares, which are in most cases the cheapest Rarities and the first go to for new players.