Yes.
Is it publicly known why? No.
Have some of the girls resurfaced elsewhere? Yes. Head over to the advertising section and look for Forever Escorts and Socia MTL.
The website still exists but a very significant number of XO's girls headed to other agencies. XO had no girls on schedule since a couple of days before the Montreal grand prix last June. This is quite indicative of XO's current situation and it's future.