A phrase or neologism which describes obsolete technology-related neologisms

Solution 1:

I might suggest referring to such items as paleologisms. It's listed in Wiktionary (and has been for some years), but not in more traditional dictionaries, suggesting that paleologism is also a neologism.

Paleologism: A phrase that was coined in the past but is now obsolete

Solution 2:

You could say passé

out-of-date: passé ideas

Collins

Or you could say that's so last year! [or some other ancient period]

Wee and Ying at ScienceDirect.com

You could say old hat, but old hat is probably old hat by now.