do we now banThe Merchant. Of Veniice because antisemites might like it?

If it came to be something antisemites actually used to rally round, then yes there would be many occasions when it would be a bad idea to perform it, and it would be unlikely that many theatres would; it would occupy the same museum-piece territory that Little Sir Hugh does in British folksong. That isn't happening though.

Whereas British racists (like at least one participant on this thread) do, in present-day reality, treat blackface morris and gollywogs as triumphalist emblems.

The German state, in 1945, had no problem with banning a tune composed by Étienne Méhul in 1807 for an opera in which the heroes are all Jewish. They banned it precisely because the Nazis liked it.