That's an odd sound propbeanie, and s7rikeback....almost like compressed air escaping.
However, I've never encountered it. I've started many new Campaign "starts" to confirm equipment/upgrades lately, for all of the possible years.....never heard that before.
I've also got my recent Single Mission with the Yubari for checking hydrophone use, its not in it either. But I'll admit, I've not tried the other Single Missions as you did in the video. I'll download the latest FOTRSU when RR puts it up with the Asashio Skin Fix, but that sound isn't on my computer, that I can tell for now?!? I'll have to do more looking to see if I can get it.
I'm on my "Day of Duty" (babysitting the grandkids), so I'll not be able to run a complete check until later this evening. But, its odd I've not run into it before?