Race changing to follow the meta is always going to be a rat race. ZOS is always going to change something and, unless you are score-pushing, race won't make a huge difference unless you are completely unoptimized (like my Breton Stam Sorc ).

So if I peer into my crystal ball of "What's ZOS gonna do to the meta in the future..."

It's murky.

Khajiit DDs tend to rise or fall based on how ZOS is handling crit in any given patch. Altmer don't reach the same heights as Khajiit on a buffed-crit patch, but don't suffer as much on a nerfed-crit patch.

If you like your Khajiit, I say go with it. It'll do high enough DPS, though it's more prone to getting nerfed/buffed when ZOS messes with crit.

If you want a change, and you want a stable, solid magicka choice who's probably not going to get dramatically nerfed from patch to patch, Altmer is the way to go. You'll do reliably high DPS but not necessarily top DPS.

If you want to race change for top DPS, it might be worth experimenting on the PTS or asking on the PTS forum if anyone's run a racial comparison for this patch yet. I haven't seen a thread for that yet, but I may have missed it.

Only reason I have found to change race from a non-meta but viable race is sustain. High elf is currently the meta for damage for magblades. Breton is the meta for sustain. Dark elves and khajit are just fine.

I wouldn't change for meta, but what do YOU want? The superior looks of khajiit or the meta race for magic?

Altmer is best in slot and will stay next patch.
At least that's the current state of PTS.
But you can definetly wait with your race change until it matters and see how things evolve.
If you are just raiding to clear hardmodes and don't care about scores or triple achievements Dunmer, Breton and Khajiit
are perfectly fine.
Even if you are doing triples there are 99 things that are more important to optimize first instead of race.