In truth, the "DEI" programs at most tech companies were not much more than PR window dressing. I don't know anyone who worked at Meta so I can't say for certain, but I suspect that in practice, Zuck isn't rolling back very much that actually existed except PR posturing.
This is still another "mask off" moment for anyone not paying attention. Every big tech company and CEO wanted Trump back and worked diligently to ensure that happened.