Yes, this is a joke - implying that his stance on DEI is self-serving and simply changes with the political climate. The physical appearance change is more superficial, but could also be seen as a change in PR strategy.
The joke above was that in a phrase like "Meta's Mark Zuckerberg ...", the first word is unnecessary because he's one of the most famous people in Tech, if not the country in general.
I guess my problem is that I had no idea that he changed his visual appearance so these references just confused me. I'm not really following his personal life.