You just say it was "dead" so basically they are not functional nor have value. Since it will not harmed your MyEtherWallet in the first place then let it rest there for long time since after all, you can't do anything to them.

The only annoying thing is here if you hold lots of dead tokens (not by quantity but for each tokens), it will be a long list on your token list whenever you are viewing or checking your ETH address at the explorer.

But for me, I don't mind. I also have lots of "dead" coins on my address. If they will soon revived then good although most of them are impossible to be brought back based on my own view.