This is a very good article that explains what airdrop is and what the problem is. I'm not an iphone user so I had no clue about any of it before.

I remember sending pictures to friends since bluetooth was on dumb phones, but apple really needs their own special name.

I keep airdrop off primarily for battery conservation and to avoid false/prank drops, but it’s nice to know I’ve been avoiding this risk as well.

Unfortunately most iPhone users I know forget airdrop even exists and it just stays on constantly.

Why not just add a timestamp that rotates every, say 5 seconds, to the hashed data?

That would make it infeasible to precompute the table permanently (it would have to be precomputed for a very narrow attack window, which is still better than nothing)