Speaking purely outside of Abyssea, this is true to an extent cid, unlike back then WHM has access to most of RDM's means of MP longevity. The fact that all jobs do now means they no longer have to heavily rely on RDM to support them like in the olden days. However there is a degree where the ToAU days could happen again when you consider the following

-HP pools are not 2-4k outside of Abyssea giving Cure IV/V greater impact
-RDM is still the king of mp longevity
-Buffs last longer giving greater mp returns and more casting leeway
-More available fast cast and cure potency gear

RDM might NOT be the best of the best at curing, but as long as the payload is manageable where one person can take sole responsibilities for the mage duties most wont think twice about giving up a second mage for another melee even if it's less than optimal or detrimental to performance. And sad as it is to say, most people have not grown out of the bird camp mindset even with the introduction of Abyssea, it just pushed other jobs into the bandwagon positions with triggers and high DPS/Nuke/Cure numbers.