Sorry, but no, they did not. (Yes, I read that topic the day it was posted.)
That announcement says that there will be a weekly rotation, same day each week.
Mirages of Omega identified separately from Rare Quest.
Mirages will be in the rotation but is still not a Rare Quest.
The announcement was that on Wednesday (yesterday) there would be an extra Rare Quest.
If they had said something along the lines of “The new Rare Quest rotation will start on Wednesday with Mirages of Omega.” then fair enough; but they didn’t, they clearly stated a Rare Quest and then failed to deliver on the created expectation.