Again, shifting the power from oGCD to GCD doesn't mean deleting oGCD's. It just means toning down the potency of oGCD's so they're not as strong as your strongest GCD's (Or stronger)
Causing you to want to target large amounts of missing health with a GCD heal, possibly supplemented by weaving oGCD's. Rather than leloGCDfullheal.
Parry was a horrible tank stat because all it did was provide RNG mitigation. Meanwhile, the meta for Blue DPS was still stacking damage because what even is a Tank anyway?
CD's can be shorter, if encounters aren't all about "Who can immune the most actual threatening attacks". Especially if more consistent mitigation is relevant so giving up passive mitigation (From, i.e. Tenacity) for shorter CD's for to be able to more freely use said CD's to mitigate passive damage is possible.
Also, TBN is stupid good because it has insane throughput, up to double the strength of other Blue DPS's similar CD's.
Though, going down this route can beg the question "Why even have the Healer role?".
If healing requirements are kept minimal, why not just actually make them into Green DPS? Just give everyone the Echo bonus from solo duties that auto-heals them.
Why not go further and delete Tanks too, heck, bosses already auto-position themselves or are stuck at the side of an arena for the most part. Just delete their auto attacks and Tankbusters and make them simply sit there and spam DDR mechanics at everyone.
Why would SE continue to try and make Healers and Tanks relevant and fail, when they could easily just embrace the Blue/Green DPS memes and just actually make everyone a DPS?
It'd instantly fix any issues with DF queues too, which is one of their primary concerns, making sure that DF is full of people so newbies can finish their MSQ's.
It might seem like I'm just being facetious, but this is actually something they could consider.
Given how ShB changes have affected the Healer population in DF content and how much difficulty they've had in balancing (The reason why no 4th healer in StB or ShB has been "We need to focus on healer balance") AND given how so many people are asking for more complex healer DPS rotations, why not just go the easy route and make everyone a DPS outright.