So, here Alduin gets thrown though time and space. While this is going on Dragons are killed off. Thus comes Skyrim. Alduin returns as fortold  and starts doing what he was created for. Then you would think he was like, The heck?? Where are all my kin? Then starts resurrecting dead dragons. Was the shout he used to resurrect them more of a rase the dead? Or do you think they got there "Life" back and started re-populating the world with dragons?

I know it's just how game game forwards for the sake of story, Just was wondering.

Their life was fully restored they are not undead, however repopulating will not be readily possible as dragons are physically asexual meaning they cannot reproduce.

is this another episode of The Big Bang Theory?

Maybe Alduin's Fus Ro Dah give the dead dragons life.