In all of our pre-covid sailings, I sent an email request for a table for 2, about 10 days out from sailing, to the rcldining@rccl.com, included our names, sailing date, ship and reservation number. Within a couple days I received a reply confirming our request and most times listed a table number. Most cruises were on Oasis Class ships, but not all.
Fast forward to our first cruise post-covid on the Oasis, I sent the same email request to the same email address I had always used and heard nothing back. I sent a second email about a week later, only 6 days out from the cruise, and still no reply. As soon as we boarded, I looked up in the RCL app and found our table number and proceeded to check the actual table in the dining room. It was a table for 4, not 2 as I had requested.
Right away, I went and waited in the line to talk to the dining room head waiter. He told me there were no tables for 2 available and he would put us on a waiting list and get back to us within 24 hours. We never heard back from dining at all. I have to admit I never checked back either, but we ended up with nice table mates and made the best of the situation.
Maybe we'll have better luck next time.