This is actually true, we have never in WoW’s history changed a dungeon’s lockout timer like this, so there was a degree of uncertainty on what exactly would happen. Regrettably in our testing we did not encounter the issue we are having today, but are working hard to resolve it.
One thing I did want to also clarify is that even if you had your Gnomeregan raid reset this morning as expected, it is correct behavior for your new Gnomeregan lockout to reset again on the morning of Thursday Feb 22nd, the same day as Blackfathom Deeps.
This is because all raids with a 3 day lockout timer rollover and reset on the same day and always have since 2005. So BFD and Gnomeregan will now always have the same reset days, and these raids will also line up with AQ20 and Zul’gurub later on down the line when those higher level 3 day lockout raids are made available in Season of Discovery.