What's the goal?

Nouveau is a example where progress happened in different stages

a) A few people participated in writing a completely free driver
b) Others participated in writing a free replacement for the firmware

I am suggesting that the Radeon driver can progress this way as well and
since the advantages of the freedom is here directly visible to end users
(ATI lags behind in their proprietary driver releases compared to new X
releases and Nvidia proprietary drivers are often problematic as well) they
will see that it is the more sustainable path

"Now, I don't know whether Fedora shipped the non-Free firmware for b43. If
it did, as I assumed"

Your assumption here is wrong because the non-free firmware for b43 is not
redistributable and this is not going to be acceptable for Fedora even with
the firmware exception

If Fedora included the non-free b43 firmware somehow then Free replacement
would be actually a regression not in freedom but in the user experience
since the free replacement does not support all the hardware that the non-
free firmware does but in this specific case freedom leads to a better user
experience and same in the case of Nouveau since Fedora never included the
proprietary Nvidia driver

I am suggesting that freedom can lead to a better user experience which is
possible and desirable and we need more of that and hence I consider any
effort to write free firmware replacement as strongly complimentary and
interconnected to whatever you have been doing and I am recommending that
you consider participating in such efforts