I say no.
BlackBerry 10 is supposed to be able to run Android apps, and we don't accept questions about that here.
Stack Exchange sites do best when they're focused enough that they can attract experts, but not so focused that there's not enough content. I have a feeling that Sailfish-related questions would simply languish here, unloved and unanswered.
(If it's big enough, suggesting a Sailfish OS site at Area 51 would not go amiss.)
But no, I don't think Jolla or any Sailfish OS device is on-topic here.