This is very common issue from Android hardware manufactures. They are quick on new devices, but if device is one year and older they not speeding procedure. Apple is the best on own devices with updates.
I don't expect yo get update as quick as S21 or whatnot. But if Samsung going to make a statement that Note10 series will get update in January, I expect it to be in January. Not in January of some versions of Note10 but not others.