This might be a controversial opinion, but I'd rather see them delist us. The exchange used to be good, but it's pretty sketchy now (what with the pay-to-get-listed, random multi-week "holidays", the short notice they give people to withdraw delisted coins, etc.) and the volume has been terrible there for ages because nobody trusts them.
I say let them delist whatever they want, and here's hoping they go belly-up soon. It will save newbies to the crypto scene a lot of pain later.
RE: Gridcoin & C-Cex (Update: Resolved, GRC Stays as explained by @barton26)