Your 2020 MB will work indefinitely for tapping into parks and Lightning Lanes, opening resort room doors, and charging to your Disney resort account - anything where you tap Mickey to Mickey. The only thing that can wear out is the battery for getting long range photos like at SDMT, where there’s no tap point to claim your photo. That battery usually lasts 2-3 years, so your 2020 MB should be fine for 2022.
PS you shouldn’t need to re-enter the number into
MDE. It should still be listed as Active under your list of Magic Bands and Cards in MDE. If somehow it was deactivated, just click to make it Active again and you’ll be good to go.