Nope, they didn't. They patched the bug since like what? 2018? Invisible skins are super darn popular back then thanks to that dude with like a million subscribers and like 300k views on average. Basically most servers at that time doesn't have anti invisible skin plugin (or whatever you wanna call it) and so he abused it and posted a video about it. It's a total mess. Mineplex is filled with people with invisible skins back then lol. I've once found like 4 people with invisible skins at the same match and we're all running around with compass like an idiot lol.I'm pretty sure Cubecraft allows invisible skins currently but was looking into it
IT's also possible that it could just eb a bug