I discovered an issue over the last week when attempting to use Apple Watch for airline boarding passes. It seems that the gate scanners Delta uses in Orlando which have an arm that raises the actual scanner up above a platform and you need to put your boarding pass under it with the barcode facing up do not support the use of Apple Watch for boarding passes. It seems that the actual barcode is too close to the scanner when it's on your arm and it cannot be read. I've had to use the phone on both flights out of Orlando in the last week.
The first time I used it last week, I just wrote it off as my error and switched to the phone quickly so as not to 'that guy' holding up the line. Tonight when I tried again, the gate agent told me they do not work. I then pulled out the phone quickly and it worked fine.
Last week I was also in Salt Lake City and Portland, OR and both of those cities have scanners that point up so I could put the watch over the top (barcode facing down) and it worked just fine. I'm on my way to Atlanta and then Nashville as I type this and will add an updates on things along the way since this is something I never thought much about but does introduce a compatibility issue with Apple Watch.
BTW, all TSA scanners I've encountered so far point up and they work just fine with Apple Watch for boarding passes at checkpoints.
I normally fly Delta only so I'm not sure what (if any) impact this might have on other airlines at MCO (or any other airport) but wanted to pass this along as information for others who might be headed to Orlando (or anywhere else for that matter) and hoping to use their Apple Watch for boarding passes in the future. When you arrive at your gate at any airport take a look at the gate scanner to see which direction it points. If it points down toward a surface, just use your phone; if it points up without obstruction above it you're good with the Watch.
UPDATE: it looks like Atlanta has the proper type of gate scanners (pointing up, without obstruction) so I'll be able to use the Watch (if we ever get out of here).
Also, an unrelated anecdote- I had ordered a couple of spare bands to go with my Apple Watch and got notice today that they are both preparing for shipment. Looks like things are starting to loosen up just a little.