http://www.smogon.com/forums/threads/usage-based-tier-updates-for-june.3606072/

Mew moved from UU to OU
Beedrill-Mega moved from OU to UU
Sceptile-Mega moved from OU to UU
Mamoswine moved from OU to UU
Muk-Alola moved from OU to UU
Clefable moved from UU to OU
Salamence moved from OU to UU
Kyurem-Black moved from BL to OU
Steelix-Mega moved from OU to UU
Buzzwole moved from OU to UU
Pidgeot-Mega moved from OU to UU
Crawdaunt moved from BL2 to UU
Houndoom-Mega moved from OU to UU
Smeargle moved from NU to OU
Keldeo moved from UU to OU
Bisharp moved from UU to OU
Pelipper moved from OU to UU
Xurkitree moved from OU to UU
Nidoqueen moved from NU to UU
Audino-Mega moved from OU to UU
Gengar moved from UU to OU
Swampert-Mega moved from OU to UU