I think by this stage we can kind of handwave the discrepancy away like what Moose said: Evil!Derplander and his ilk are from a parallel Hydaelyn so as things already diverged from 'our' Hydaelyn, whose to say that it was the female GLA in the 1.0 opening that Derplander did not end up meeting and instead reunited with the snooty male elezen from the Adventurer's Guild? (And thus he then became the BLM not the female elezen GLA from the Echo scene). I admit, I'm grabbing at straws here...

Also, furthering the handwave, is it's sadly not the only mistake in narrative that Square Enix Visual Works inadvertently made - the Heavensward opening after all shows Hraesvelgar (along with a whole swarm of his clones!) attacking Ishgard, not Nidhogg who it should be - apparently this was simply due to using the wrong concept art and by the time SE Visual Works realized the mistake, it was too late to change the CG so they left it in (and simply disguised Hraesvelgar with red colouring to make him seem like he's just a generic dragon). But it's still glaring if you compare it with in-game events.

So it shows don't take what is shown in the CG videos too seriously in regards to in-game events, they're pretty stylized for dramatic effect.