55k is for those that filed right after Q4 2022 ended, like me. Even that number has already shrunk because they have worked on probably ~8k cases give or take since then. So I probably have about ~47k in front of me. You on the other hand filed earlier which means you are further ahead in line. The backlog at the end of Q2 2022 (end of March 2022) was about 43k. Now subtract all the people whose cases have been closed (about 7k per quarter since then). It would be about 21k. So yeah, ~20k sounds about right.
This is all according to how I have understood this process to work so far. Anyone reading this and who thinks I'm wrong can chip in obviously! I'm not very good at math but this immigration journey is definitely making me a math wizard all of a sudden 😂