I mirrored the source rpms down and did the following for 8 and 9-stream.
```

$ for i in AppStream BaseOS PowerTools; do echo $i; find ./$i -type f -name "*src.rpm" | xargs rpm --nosignature --qf='%{NAME}\n' -qp > /tmp/a-$i; sort -o /tmp/a-$i -u /tmp/a-$i; done

$ sort -o /tmp/a -u /tmp/a-* ; sort -o /tmp/b -u /tmp/b-*

$ wc -l /tmp/a* /tmp/b*
  2652 /tmp/a
  1740 /tmp/a-AppStream
   536 /tmp/a-BaseOS
   503 /tmp/a-PowerTools
  2273 /tmp/b
  1620 /tmp/b-AppStream
   399 /tmp/b-BaseOS
   295 /tmp/b-CRB

$ comm -1 -2 /tmp/a /tmp/b | wc -l
2090
$ comm -1 -3 /tmp/a /tmp/b | wc -l
183
$ comm -2 -3 /tmp/a /tmp/b | wc -l
562

```

So 183 packages were added to 9 that weren't in 8 and 562 packages were 'removed'. Some of those are obsolete packages like

python2, python36,python38, gcc-toolset-9, gcc-toolset-10, autoconf213. Others are module things which aren't shipped already.

That leaves about 500 source packages which aren't even built internally so aren't going into CRB.

--

Stephen J Smoogen.
Let us be kind to one another, for most of us are fighting a hard battle. -- Ian MacClaren