Message when approved for a team refers to "status of your" non-existent "membership"

Recently I applied to join a restricted team, and I was approved by one of the administrators. The e-mail message I received said: "The status of your membership in the team <team name> (<team ID>) was changed by <approver> (<approver ID>) from Proposed to Approved." But that's impossible, because until now I wasn't a member, so there was no "membership" to change the "status" of. That might be how it's represented in the Launchpad database, but it doesn't make sense for humans.

The message should instead say something "<approver> has accepted you into <team name>. Welcome!"

It may save time to fix this bug at the same time as bug 184795 and/or bug 184798.