It might be the paci, though it could be that you are experiencing a bit of 3-2 routine silliness. On catnap days that might be causing him to wake UT, and if he doesn't get the catnap and you don't compensate with EBT, he may be waking OT. I would be tempted to try pushing his naps a bit later gradually (10 mins or so every few days) aiming to even up his day with 2 naps and drop the catnap. A very textbook routine would be WU 7, naps at 10-11.30 and 2.30-4, with BT 7. I would probably do that first and see if it solves the wakings, but if not the I would probably do the swaddle and paci all at once - no point in having to do it all twice!
Good luck for your surgery - I hope all is ok x