This is certainly more pushed than usually.

See this Gatherer search.

As that search shows, 2/3 blue flying creatures at common usually have some restriction on what they can block. Making a better Talon Trooper doesn't seem much, so I guess it could be just thrown out there. I think it has more to do to show people that has the "worst" creatures.

To make links to Gatherer searches (which include square brackets), use the syntax where you type [description][1] , and then on a separate line, go [1]: followed by the full URL. I fixed the link above for you.

Or just link to MagicCards.info ;)

It's probably worth noting that while some of it has to do with blue having the "worst" creatures, some of it also has to do with just how good flying is in a limited environment. 'Can't be blocked, except by' does wonders for a ground stall.

I'm not saying that 2/3 for flyer is good or bad, because I don't know. I'm just saying I get why Nimbus of the Isles was made.

Also, Wind Drake is like the go-to example of a reliable limited card. It was even just reprinted in Kaladesh.