Our Tuesday 1/18 flight (United out of EWR) has just been cancelled.
Next available is Wednesday 1/19, same time, but no Economy seats available so we had to upgrade to Economy+..
We had submitted our EHAS forms, my wife Cleta's was approved almost immediately - mine is under review.
However, since arrival date has changed, we have to start from scratch by filling out new forms.
Bottom line is we'll have more legroom but one less day of vacation.

UA cancelled and are you having to pay extra for better seats because the others weren't available? That doesn't make sense, that should be their issue.

My guess is that the SXM people that handle the forms are getting pretty used to all the changes.

Sorry about losing the day of vacation.
Any reason given for the cancellation?

We didn't ask, but I assume it's because of COVID related staff shortages. We could have kept the original price, but would have lost yet another day. In the end we got reductions on the car rental and hotel, so it almost evened out. This was supposed to be a mini vacation anyway, celebrating Cleta's retirement. We also plan to move and it will be the last time using EWR, which always worked well for us.