If you start an Airdrop transfer from the Mac, there is no way to choose the target machine with any key commands. This it is something that many newer users will not be able to work around, causing them to possibly conclude that Airdrop is not at all usable with VoiceOver.
Bug First Encountered
How often the bug occurs
The only way to select an Airdrop target I know of is to interact with the table of machines, find the one you want, interact with that row, then route the cursor there and simulate a click.
I've also incountered this bug, and no matter how hard I try, I can't seem to find my phone with the airdrop feature. Rather annoying it is.