When Vopsbot (irc nick sirenbot) restarts, it rejoins its channels but doesn't automatically recover its privileges. In the private SRE channel, that's not a factor, because anyone can update the topic. But in #wikimedia-operations and #wikimedia-sre, mode +t is set, so only ops and half-ops can update the topic. The bot is not automatically opped, so its topic updates fail, and the topic contains incorrect information about who's on call.
We can probably fix this either by configuring chanserv, or via ircservserv, but I don't have the rights to do so.