Perhaps "gallows humour" is not quite the correct description.

These are closer to that definition...

Murderer James French has been attributed with famous last words before his death by electric chair: "How's this for a headline? 'French Fries'." Likewise, when a Jewish mob boss George Appel was electrocuted, his last words were: "Well, gentlemen, you are about to see a baked Appel."

I should probably have called it "Disaster Humour"
In the olden days it probably took a bit longer for the jokes to spread around than it does nowadays thanks to the internet.

I think these sort of jokes occur in most cultures.
Schadenfreude? or a natural response to "always look on the bright side"?

As to the puns on Asian names I believe that other races take the piss out of John Smith and other wacky Anglo names.

Unless you are getting your material from the Readers Digest or a Chinese Cracker (oops!) then most jokes are liable to offend SOMEBODY and an apology might be in order.

If a joke causes vicarious offence among the odious PC brigade then (IMHO) they are welcome to go and get intimate with themselves!