@bdb
I think behind Amigakit's "We have a licence for the A4000 ROMs" statement is a more complicated one, such as "we have a license to reproduce the original Kickstart software in a way functionally equivalent to its original distribution form, for replacement and/or upgrade purposes blah blah etc etc".
I'm sure the legalese behind the license fully documents the reproduction aspects (e.g. could explicitly not allow to reproduce Kickstart as files, like Cloanto is licensed to do in Amiga Forever, or could even cover details as to what kind of sticker should be affixed to the chips).
This would make the distinction between ROMs, PROMs, EPROMS or EEPROMS immaterial, as such a reproduction license would conceptually refer to the software in its abstract form, with the specific distribution form being just a defined aspect of the reproduction.