I don't think the Wine developers were simply being hostile due to a dislike of the concept, I also agree that a Wine Wayland driver seems weird. And yet, here we are: when I use it, it seems to work almost exactly like you'd hope. I'm not sure if the reason this has changed is because there are new standard Wayland protocols that help with some of these issues, or if they just came up with clever workarounds (like always anchoring new windows to be relatively positioned or something.) Either way, it works.

I have heard there are still some tricky impedance mismatches though. I have no idea what they're doing for the system tray, for example. Right now, if I cause a tray icon to exist in Wine with Wayland patches on SwayWM, what happens is I get a "Wine System Tray" window. Not ideal to be sure.