why doesn't d-i include firmware-b43-installer and firmware-b43legacy-installer?

[Tomas Pospisek <tpo@sourcepole.ch>]

In #740499 Chris Bainbridge writes that:

> [...] but firmware-7.4.0-amd64-netinst.iso does not contain
> Broadcom firmware (at least not b43).

I can see that there are firmware packages for Broadcom b43 in contrib:

https://packages.debian.org/search?suite=bullseye&section=all&arch=any&searchon=names&keywords=firmware-b

Could anybody in the known comment why those firmware packages are not 
included in the non-free installer images? Is there anything preventing 
their inclusion? Or asked in a different way: could they be included so 
the Debian installer supports the users with that hardware?

Thanks,
*t