Yeah I called yesterday and was told that an agent accessed and reviewed the file on January 2 but then didn't finalize it or anything. She also said that until the agent goes back and finishes the reviewing, there is nothing she can do as the agent didn't leave any notes or details on the reason why the file was not finalized and asked me to call back on Monday if I still haven't got it yet. So I am planning to give them an extra day and call them on Tuesday.
If it was approved, datewise, January 2 actually makes sense as the applicants from my timeline pretty much all got theirs either before or around January 2.
The other reason why I am waiting until Tuesday is that
@xander88's OWP approval took 125 days and my 125th day will be on Tuesday.
So hopefully, I'll be updating you guys with the good news by then.