I'm sorry, but personally I don't really see the pros of the MCH changes as if something as strict as SMN can do the phase, so to can SB MCH.
In fact, since Wildfire was actually on a 60 seconds cooldown the past expansion, Wildfire can easily be put on one of the aqueous adds, and then bursted down that way. You'll immediately be able to put on Gauss Barrel on at the beginning of the next set of Adds, and then overheat Rapidfire again on the third wave of adds. If it's not enough, the devs can easily make it so that the adds aren't immune to Heavy, so that puts a lot more gameplay in the hands of physical rdps.
And in terms of boss becoming untargetable, old MCH can easily just early Flamethrower into Overheat in bosses where they jump early, like Suzaku Extreme.
A MCH with the old 60 second rotation will fit into the current sandbox just fine, just like SAM GNB and DRG with their 6 GCD combos that can't be interrupted.
Taking out satisfying and engaging gameplay from a job and condensing it to just two buttons is one thing I don't agree with even if I do understand that they do need to appeal to the majority.
I just wish Square would STOP reducing job kits to one or two buttons and just start adding complexity again.
It's frustrating seeing something you've loved so much turn into a completely other thing to appeal to a lot of people, it's like turning BlazBlue into Tekken.
It's dumb.