The difference now is that when Meghan joined the family, Harry did not feel he got the support from his family and "the firm" when the media and others were criticising her. I imagine he didn't feel he owed them his loyalty any more when he didn't have theirs, and he now has the ability to financially support himself, so he left.
and good for him. It's obvious the treatment of Meghan was abysmal. The jokes and bet about the colour of their child, the blackamoor brooch, the video of William turning his side to Meghan and ignoring her while staring at the cameras. If that's how they behaved in public, you can imagine how it was in private.
There was enough speculation when Kate shrugged William off in front of Mary Berry. Why wasn't that scene cut off is anyone's guess.
Meghan behaved impeccably in public, turned up, did all the engagements required of her, and more, but was abused because she dared standing up for herself.
Harry was probably a bit naive to expect family support when he married a divorced mixed-race american, but I think it really damaged to royal family to be so out of touch with the real world.