Nope. I've seen good projects delisted from the major altcoin exchanges and still going on with active development.
But delisting usually comes with a blow in the price; the more and bigger the exchanges delisting, the bigger the damage. Maybe some coins can recover from that, but some surely not.

Please don't take it as a trading advise. I don't tell you should sell or not. I don't know the project/coin. It's absolutely your decision. And imho it's a tough one.