Drop in your alliance's guild names (one per line) and find out which team each one landed on after the relink, plus the tier, score and top guilds on every side of the match. It all runs in your browser, so nothing leaves except calls to the official GW2 API.
Names need to match the in-game guild name exactly. The API search doesn't do tags or partial matches. Up to 60 guilds per run.
Paste some guild names above and hit Check. Results show up here.