Wild, I've def heard of some reasons how the Fermi paradox could be resolved, but I missed this explanation. A quick headline scan of the wiki article also doesn't mention it. [1]
You'd think that 94% of the observable universe not being reachable would get more of a mention. Granted, we can still look for artifacts such as radio signals or something similar, but it does seem to cut out why a type 3 civ hasn't shown up at our door.