Are you changing Tier 6 drops? like SSC?
The person is asking if bosses will drop an additional tier token. Blizzard has been doing that in later phases. I'm going to guess that they'll probably when they drop Sunwell in June.
Can we still do the quest chain to get the attunement even though attunement isn't required to get inside anymore?
Quest should still be there, they rarely remove such things just the Attunement requirement flag on zone ins.
The quests, and the title for completing the attunement, were available until Wrath released back in TBC originally. The same should be true here.