Cloanto are not the copyright holders of old Amiga OS, they just have a license to distribute. I would expect that for every copy of Amiga Forever that they sell, some money tickle in the direction of Amiga Inc. OTOH, Amiga Forever also includes an updated and altered kickstart, named kickstart 3.X, which pretty much is an OS 3.9 kickstart - I do wonder what legal rights Cloanto has to sell such an altered kickstart, I highly doubt that it too is coverered the original 1994 or so deal they have.
Oh, and I got my copy of AmigaForever for free from Cloanto, in exchange for linking to them from my site, and I assume, from my involvement in back2roots back in the days. :-)