This is probably the preferable way though as it’s shorter than the first URL you provided.
I don’t think there was a deprecation announcement. If there was, it was probably in a release note a while ago (so what I’m saying is that they probably didn’t make an official announcement if they did deprecate it)
I do remember loading in an animation recently using the rbxassetid notation, and it did work. Strange how it doesn’t now apparently (cant test it since it’s like 10PM)
rbxassetid:// is more appropriate and may result in faster loading times because it’s a direct reference within the Roblox environment. On the other hand, if you’re sharing links outside of Roblox or need to access assets from a web browser, http://www.roblox.com/asset/?id= is the way to go.