The new major version of sqlalchemy was recently released. This release contains several breaking changes and we have to fix multiple deprecation warning to adapt to the new versions.

https://lists.openstack.org/pipermail/openstack-discuss/2021-August/024122.html

This work has been started in a few projects such like oslo/neutron/octavia. We first have to evaluate amount of work we need and spend some time so that we complete migration before the global OpenStack project decides to bump the version.