We wanted to give everyone an update on the guild trader swap issue that occurred on the PC-EU server last couple weekends.
Jessica Folsom, ESO Community Manager
We made a few adjustments this week that should help – with a few more in progress – but there is still a chance the issue could occur again this weekend. Our Engineers will be watching the switch-over and we are prepared to resolve the issue on Monday morning if it happens again, just like we did this week. Thank you all for your continued patience.
Source: https://forums.elderscrollsonline.com/en/discussion/comment/6591833/#Comment_6591833