That doesn't seem plausible to me when you consider that opera is the plural of opus. Afaik in early latin, /s/ often went to /r/ when it fell between vowels. That is why it has /s/ in the nominative but /r/ when you start to inflect it with suffices.

This happens a lot for third declension nouns where nominative ends in -s (opus is one such example)

Other examples of this pattern:

Corpus -> corporem (not *corpusem)

Venus -> Venerem (not *Venusem)

Flos -> florem (not *flosem)

Colos -> colorem (not *colosem)

Or more simply, we can look at opus and see it comes from a different PIE root from cyber. (When i look it up, the former has a root meaning "work", and the latter has a root meaning "turn")