I agree.. twists don't always have to be negative, they can be positive. or just different and unexpected in a way that makes that gives you something exciting or amazing.
I would find such a development intriguing, and possibly quite exciting if it gave me a cool new model of night elves, a layer of kaldorei fantasy fused with fresh tangent of new angle with the naga - ala Atlantis in Aquaman style.
What if out of this the night elves who have been depleted severly in numbers got a genuine allied race of elves of their history (after losing the nightborne to the horde). I know it's wishful thinking, but I think the night elves having a naga-elf subrace ally would be cool and could be part of a larger set of improvemntes that boost htier fortune. they'd have to be night elf calibre - so maybe touched by Elune - cos I don't see how the night elves would trust former naga - unles they showed some incredible virtue with Elune approval. It also gives a chance for their restored highborne order to take a lead and show us a bit more of kaldorei arcana.. and how they perhaps differ from their shal'dorei horde counterparts. I view the new night elven highborne like the Farondis we met in Azsuna, talented night elven mages who have returned tot he nobility the highborne had before addiction fuelled hubris and arrogance took a hold. Arcane midned and talented, but noble, revering the wilds and Elune, pro harmony - arcane wielding wonders and expertise, focused on building, discovery and excellence.. amongst them the Moonguard order is restored, and they are the ones that focus on battle, thanks to the Moonguard leaders surviing in legion, to train new arcane wielding night elves.
however the nnaga elves are a whole new culture, having some of the traits of their pre-sundering kaldorei culture and acumen, but with new things, new levels of advancements etc..
I've overdone it here, but it was just an example of what I would find exciting or get excited above.. especially if they looked like this:
I loved this concept art, especially the faces and features.. felt night elven, yet naga.. with these elves able to switch to full naga..Strategically with this sub-race part of the night elves, it gives them a high degree of sea mastery too and something different to compliment them