I overall do agree with gating fights kinda like T5 does with T6+, but not keeping them gated forever. The purpose of the gates is to make sure people learn how to play well enough that they have a chance in the next tier, but as time goes on, these gates become frustrating obstacles for obsolete content that very few people run. I think the best timing to remove the lockout on T6 would actually be 1 patch before T6 gets nerfed so that everyone who is so inclined may try T6+ as is before everything starts getting wonky with echo.