Edit: Blue response below clarifies the information, I am leaving the rest of the post for the reason the blue response happened.
Chronoboons will not be usable during the pre-patch, that means if you plan to raid at all during the pre-patch for the fun of it to have TBC talents in 60 content, you know for, fun, something blizzard doesn’t understand because their metrics cant quantify it.
You will have to get your buffs the old way, risking dispells and have a summon train.
This also means any dreams of chronoing buffs to go into outlands with and do the first few dungeons you run, with full world buff timers, are dashed. They already do not work after level 63 and are removed upon entry into RAIDS. They had to twist the knife a bit more into the fun.
It was a good 3-4 weeks of chronoboon bliss, thanks blizzard, you killjoys.