regarding aerial vectoring of nitrifiers: the individual cells aren't in the air BUT nitrifiers seed from the air due to raft-riding

/ they're attached to various items that do transit by air. flotsam/ bugs/ tiny bits of dirt that were wet/ all potential vectors for free bacteria who stick and ride until that floater deposits somewhere.
nitrifying bacteria have been found in the upper atmosphere riding these micro trash rafts with millions of other species of bacteria.
if you live within 300 miles of niagara falls, every breath you take is vapor + nitrifiers + whatever else.
If you're in the mojave desert, not as likely
The main source of free bottle bac/natural seeding of bottle bac isn't aerial its standard liquid contamination transfer. Because we're handling surfaces, those are full of nitrifiers by association since these items are so much associated with wet things, which is where nitrifiers originate. You do not have to be handling something directly wet in order to vector in bacteria, anyone who gardens routinely has permanent nitrifiers up under their nails, even after hand washing, and it spreads to anything you touch with the same hands.
when you make lemonade using tap water, that tap water inputs live nitrifiers into your glass due to pipe scum sloughing, it doesnt mean the water company pumps out bacteria.
They do always find a way.
Bottle bac are not providing things we can't get free, they're just speeding up the process. to wait for aerial transfer/ direct contamination transfer in a marine system unassisted w take months but it will certainly cycle given time and no other help.