-Update-
MLG has since announced Ninjas in Pyjamas and London Conspiracy to replace both the teams.
According to MLG tweet an hour ago, Team Empire and Vega Squadron has decided to pull out from the tournament due to failure in obtaining an American (B1/B2) visa. This is the second time Empire has failed in obtaining visas for all their players this year; Empire played with funn1k as a stand-in in joinDOTA MLG Season 1.
.@Team_Empire & @VegaSquadron regretfully withdraw from the XGames #DOTA2 Championship due to an inability to obtain VISA's to the USA.
— MLG (@MLG) May 27, 2015
The news of Vega pulling out of the tournament due to visa issues have been reported by DotaBlast on May 23. DotaBlast alleged that Vega will most likely be replaced by London Conspiracy, the fourth placer in the European qualifier, although no official word have been released by both the team and the organizer.
Empire's pull out on the other hand, came as a little bit of a surprise considering the Russian team was invited and had ample time to prepare for their visa.
We have reached out to MLG on Empire's possible replacement and MLG stated that they will announce it later today.
Teams participating in joinDOTA MLG Season 2:
Evil Geniuses
Alliance
Virtus Pro
London Conspiracy (?)
Mousesports
Summer's Rift
Team Malaysia
JoinDOTA MLG Season 2 will be taking place in Austin, Texas from 5-7 June. The esports event will be among many other exteme events such as BMX, skateboarding and Moto X.