I have permission from AQ to say this: Aristos Queue has no idea what he's talking about.
It's possible to deprecate properties, but we have it hidden. This was built so some of our APIs could be deprecated with the potential of releasing it in the future. When you deprecate a LabVIEW Class Property it will remove the item from the property menu and is supposed to turn the property node reddish pink (it doesn't because of a bug I just discovered). I don't remember the behavior of deprecated overridden properties.
The deprecation applies to the LabVIEW Class Property Definition Folder itself (i.e. the property itself), not the individual methods. I'm not against turning it on in the future, but I think it'd need to have significant public support before I get off my lazy butt it gets approved.
Uhhhhh...you mean like this? Seriously, this is what it looks like if you know how to show it.