We don't know enough about the history of the quarian people, or the Halo, to say about its origin.

But, yes, I can imagine a significant faction of quarians would be interested in occupying and colonizing it. There's still the attendant troubles with settlement that can only be remedied with their home planet to consider however, the faction of society that wants to retake Rannoch from the Geth, and the faction that feels it is appropriate to wander as a fleet of nomads for e'er more. But those lot can, I dunno, join up with the freespacers.

I like to imagine there's a reasonably sized freespacer expat community of quarians, even if they get tired of explaining how the Migrant Fleet is different.