Just switched to iCloud last week. Yes, it does catch-all (although it needs to be enabled through a checkbox in one of the settings menu). It also does sub-addressing / plus-addressing natively (no menu setting needed), which doesn’t seem to actually be documented but it works flawlessly for me.
I’ve been extremely happy with it so far. Pairing plus addressing with some of the filtering rules allows me to direct bulk mail to the right place automatically. For whatever reason, filtering rules can’t be done on iOS but need to be set through icloud.com (not sure if they can be set on macOS).
@JoeHill it’s rather odd how it works, as there are rules in the Mail app on macOS and they do sync. But you can only access and adjust those rules on a Mac and they only evaluate when the app is running on a Mac. It’s definitely something I wish they would add and integrate throughout all the iCloud ecosystem