Currently, the master branch is considered "upgraded" and using new FCV constants after the latest version has been applied via git tags. Ideally, we should consider the branch cut as the official transition to the newest version and immediately have access to new FCV constants after the branch cut.

As part of this ticket, we should investigate ways to resolve any redness due to upgrading FCV constants on evergreen before branch cut. Even if we don't upgrade FCV constants immediately on branch cut, it would still be useful to consider ways to reduce the amount of Upgrade/Downgrade work that engineers have to do before applying the latest git tag.