If they remove the headphone jack, it's solely for market lock-in reasons. Same as on the iPhone.
If, as you mentioned, we can already achieve wireless audio through third-parties, then how does the removal of a jack signify or aid "market lock-in"? I'm not beholden to apple to buy their headphones. Bluetooth is bluetooth. I'm not sure I see how we're being locked in to anything here. I could switch from my apple phone to my android phone with no issue. A proprietary plug, I could understand as lock-in (although I do like the "non 4-dimensional" qualities of the lightning adapter).
I do agree that the modern office space is not necessarily prepared for people to do meetings with no audio jack option. I will say, people thought Apple was crazy when they dumped the CD/DVD drive as well, but I can't say I've missed mine yet. I'm not sure I would call it "bravery", but I might call it "an unwillingness to allow the status quo to prevent our vision of progress", which sounds much more like Apple.