I updated my TS 401 3 years ago to version V5.61 and it only goes up to 2020 also, it seems there is not an update after that. I upgraded and bought a new TS 508 that can also program the MX sensors. I just updated it yesterday (8/30/2023).
I like to keep my 401 charged up and usable as a back-up and for older models still and for checking Remote key FOB (RKE & RF ) signals.