[oladon]

MW adds practically any word that someone uses, ever. And Wiktionary? Come on.

If you take a gander at WordNet or even OneLook (searches multiple dictionaries), you'll find that the majority list obsolete only as an adjective, including Webster's 1828.

However, I concur that obsolesce would have been a better choice.

[Jach]

Dictionaries are historians of usage, not legislators of language. If the communication is clear, which in this case I think it is, then I don't see a problem.

(BTW, I used to be a grammar nazi years ago.)

[danieldon]

OED has it as a transitive verb, with usage going back to 1640.

[jufemaiz]

OED > *

Sounds strange to the modern ear though.