It is a different case, as the standard serial decode functionality offered after March 1 2020 does not require any license code. KS is most probably checking the serial number to activate the standard option on new units. They added some functionality like 200,000 wfm/s and 2Mpts memory even for older units, but not serial decoding.
This is very cheap trick, as smaller companies like GW Instek released new firmware with serial decoding for the 1000X series and it activates it on all units, new and old.
It is not different. When you bought the scope you bought it as it was. With whatever options it had at the time. Anything the enable afterwards is their good will.
While you are technically correct, that's a very short-sighted way to see it, as it's a good way to lose customer trust.
But honestly, Keysight and Tek have lost the war on the entry-level/low end, and the future doesn't look that bright for them on the mid-level either. Rigol, Siglent and GW Instek offer you features on sub $1000 models that are not there even on models that cost 3x-10x more in Tek.
For example, in order to get segmented memory on a Tek scope you have to go with the MDO4000+ series. Even their brand new MDO3000 with a starting at $3500 doesn't have it.
Similarly for Keysight in order to get statistics you have to go with the DSOX3000 and above.
Siglnet, Rigol, GW Instek give you these features on their entry-level scopes.