I did some digging and found the following:
- DL522 historically has DL480 as the inbound flight, but has DL397 as the inbound flight today
- DL397 scheduled to arrive just after 3 PM HNL time, which is slightly early
- DL 397 normally feeds DL788, but the inbound for that one is DL2499 today and DL788 is not delayed
- DL480 for today landed early with tail number N191DN, but it is going on to fly DL495 instead of DL522
- DL495 normally has DL2980 as the inbound flight, but that flight is 7 hours late
Basically, DL2980 is delayed by 7.5 hours, which would have also severely delayed DL495. Delta decided to use the plane that DL522 normally uses to be used for DL495 instead, and DL522 will use the plane from DL397 instead. DL788, which is normally fed by DL397, is going to be fed by DL2499 today without any extra delays, and I'm stopping there as I'm assuming there are no further delays down the chain. Therefore, Delta traded a possible 7.5 hour delay for DL495 for a 2.5 hour delay for DL522 by shuffling some aircraft around.
TL;DR: I would not be worried about DL522 getting delayed any further as the plane that's having issues is not flying that route and DL522 just got caught in the crossfire while Delta was trying to get a new plane to replace the one having issues.