In general, if you've got an Amiga with a given kickstart ROM, you've got a license to use the corresponding version of WB. This is because ROMs were usually sold with the disk set, or both were provided with the Amiga. No need to buy another disk set.
The only time that isn't the case would be when someone bought some ROMs without buying a disk set at the time, but that is rare, and really, who is going to know or care?
