One important thing to keep in mind is that Cure V is still pretty much Cure V. Cure IV has gotten way better rather than Cure V becoming notably worse.

In situations where Enmity is an imminent concern, a bro using mostly Cure V isn't much more likely run out of MP after the changes than before. Situations that go bad due to post-change Cure V expending too much MP would have been very tense already. There's simply the new option of using an extremely MP-efficient cure instead of an extremely Enmity-efficiency cure.

Overall, I really like the implications of these changes.

Equipment will matter more now than ever, whether it's Healing Magic skill for power or -Enmity for not being eaten. There will be strategic elements in deciding which Cure to cast that weren't present before. A lot of equipment that was almost pointless before, such as Sirona's Ring and the Healing Magic skill grip, will have a reason to exist. Healing Magic skill merits will mean something other than "This person, this person is not a smart person."

One thing that really surprises me is that it appears people subbing White Mage or Red Mage will have very slightly stronger cures than before, particularly if they go the extra mile and macro in the few Healing Magic skill pieces that don't compete with Cure Potency slots to get the most mileage out of their sub-jobs.

It must have taken the Development Bro who passionately loves bad things longer than he expected to make Cure VI even worse, perhaps because it was already pretty bad, since everything else seems to be improved or relatively unchanged.