I don't think they're really 'Xaela' though as the various clan variations seen on the Source don't seem to exist on the First (or if they did, the Flood of Light probably rendered it moot).

Another species (I use the term species as 'race' isn't really appropriate with these things) that interestingly is stated in-game as to be not be native to the First (in other words, does not actually have a true counterpart race), but has only shown up recently there... is the 'poster child' monster for ShB, the gremlins!

Despite showing up frequently as annoying enemies in Norvrandt (especially in Lakeland), a Lakeland sidequest actually reveals that gremlins only started appearing shortly after the Crystal Tower materialized nearly a century before and, further more, were believed to have actually come from the Tower, suggesting the ones seen in the First are actually from the Source, that they hitched a ride in the Crystal Tower from the Eighth-Umbral Era Source timeline and are now well and truly ingrained in Lakeland, where they're regarded as pests (none the less because they have a bad tendency to desecrate graves in cemeteries, adding further misery to the already suffering inhabitants).

So, they're basically now the First's version of feral rabbits in Australia (only with a lot more bad language) ....