No further boost will be provided, boosts are fixed in stone :)
Think about it, there are so many CL cards are out there, it was a highest printed set. If you give them any boost, you will add massively to the inflation. That will be a NO NO.
What we are trying instead is to burn those excess CL cards. We did that successfully during the latest land cards set.
Maybe they give better return for burning cards then. I'd be happy to burn some of mine if I was going to get a better return on it. I mean really with all this back and forth it sounds like the biggest issue that ruined a lot of the game for people was the over printing of Chaos Legion packs. It's crazy how one thing can dominio so bad.