If Sky Tyrant hits twice in one action (e.g. when using Flurry), after resolutions, does he get to move half his speed value twice?

Yes. "Hits" is a check per attack. So for flurry, he's making 2 attacks, and on each attack as long as he hit's 1 or more targets - it qualifies as a hit, giving him his after resolutions move effect.

Is there an official ruling of this somewhere? Typically, it would say each time he hits ...

They've used plural HITS on a single attack numerous times. This is very reminscent of banking costed actions with stupid Vulture which isnt a thing anymore and really never should of been. When something is at no cost to you its also...FREE! That's right, free. I digress.

How would this read if it was a singular hit? It would still say with this figure hits X happens right? I think the EACH TIME or for EACH HIT X happens.

It isn't reading that way to me. If there's a real ruling out there, someone give it to me.

NEVERMIND...I think I found it in the mumbo jumbo of Heroclix legalise in the comprehensive rulebook 8.1g

This ####ing game...

If it was balanced, I mean limited to one move then it likely would have been written something like:

Flurry. Charge but do not halve speed. After resolutions, if Sky Tyrant hits, he may move blah, blah, blah.