I think commit 6e842759cc may have inadvertently introduced a minor bug, but unfortunately I haven't had time to test it out yet to confirm - but if I don't raise it, I'll forget. If I get time to verify this myself, I'll update/close the ticket as appropriate.

The change in the commit checks if the destination world is different to the current world, and if so, calls entity.teleport() with:

entity.teleportTo(location, cause == TeleportCause.NETHER_PORTAL);

So, if I'm reading right, the cause would suggest it was a nether portal even if you were going through an end portal to the End (when it should be TeleportCause.END_PORTAL instead).

Impact is unlikely to be massive, but could catch some people out.