Let's wait for the rest of Chronos results to roll in, I wouldn't be terribly surprised if NBN dominated less than you expect. Thing is, it's easier to counterplay and more swingy (the joke of "playing to first Astro" holds very true).
While I agree with you that Astro is a large part of NBN's dominance right now, I maintain one thing: the hardest thing to play against now, at the end of Spin isn't NBN, it's Cerebral Imaging. You can build to curbstomp NBN rushy decks and you'll be able to do that pretty reliably (your success vs. other archetypes may or may not be as decent, depending on how well you play, variance etc). Building a deck specifically to counter CI, on the other hand, will present nowhere near a comparable level of reliability in your "preferred" matchup. That, in my mind, makes it a harder deck to deal with. And, let's be honest here, CI is completely enabled by Biotic Labor.
My experience says "yes" (exhibit A, exhibit B) - that deck was built specifically to counter AstroBiotics, and has carried me reliably through two reasonably large tournaments (as large as they get in these parts of the world, anyway), where it faced all sorts of varied stuff and did just fine.
But they do have access to other tools that give you plenty of other outs, including some that give you pretty reliable ways of scoring a 5/3 from hand. Technically, that should also be considered an out once you're at 6