For EOS 2.0.x, it seems: eosio-2.0.x is develop branch and v2.0.x is production branch.
But for EOS 2.0.8 (corresponding fc @ b53dbdc):
git branch -r --contains b53dbdc
origin/v2.0.x
And for EOS 2.0.9 (corresponding fc @ a369475):
git branch -r --contains a369475
origin/eosio-2.0.x
origin/keke_epe294
So fc used by EOS 2.0.9 does not contains commit b53dbdc which is existing in EOS 2.0.8 ?