Hi everyone, we asked Rob Hinkle (Senior PvP Designer) to shed some more light on why this change was made. As many of you suspected, we implemented this change to reduce the frequency with which players abandon Warzone matches mid-fight. We found that Group Finder queues popping were a major cause of players leaving, and wanted to mitigate this negative impact on Warzones.
This was obviously the only possible reason. A far better solution would be something like above, where if your queue pops during a match, you are told you are being skipped and placed at the top of the GF queue, so you know not to requeue for warzones (because your GF is due to pop soon).
The current alternative of having to choose to wait in one very long line (GF for DPS) while doing nothing is causing both pvp and GF queues to increase on my server.