While normally making jokes after a person's death would be socially questionable, in this case Chuck Norris himself loved the Chuck Norris jokes. For me at least, a good sense of humor is maybe the most endearing personality trait. RIP
Giving people reason to laugh while you are old and dying is a superpower. I wish i will have it, too.
Fundamentally, I'd argue that very little should ever be unreasonable or out of bounds to make jokes about; what is important is that it's good humour.
Case in point: https://theonion.com/hijackers-surprised-to-find-selves-in-h...
And, as you say, in Chuck Norris' case, it's virtually obligatory.