For me, the concept is just a quick brain fart. I understand about the problems with yeast functioning properly at higher pressures - especially in stronger brews. I thought a lower pressure might prevent the alcohol from forcing itself so greatly on the yeast walls and thus penetrating and "stupefying" the yeast.
Wonder if they ever experimented on this stuff in the ISS way up above us.
as I understand it, osmotic pressure and atmospheric pressure are two different animals.
Osmotic pressure is caused by higher concentrations of various compounds one one side of a permeable membrane, this forces too much/not enough sugar/salt/alcohol to cross the membrane which can hurt the yeast, especially at various points in their life cycle.
Atmospheric pressure can also hurt the yeast but for different, more mechanical reasons, just too much stuff pressing in on them from all directions.
Bigger brewers ferment under some positive pressure because it inhibits certain yeast character expressions, primarily ester formation, so you can ferment warmer without getting ester bombs. warmer fermentation temps lead to faster attenuation.
Brewers also choose open fermentation to reduce the atmospheric pressure on the yeast to encourage yeast expression. This is done by Sierra Nevada for Bigfoot and Anchor Steam across the board. Also many british brewers.
it's an intriguing question and if you have the time and inclination I'd have at it. It would probably be worth your time though to review the literature that already exists in the trade to see what others have done around this already. not to say you shouldn't do it if someone has already tried it but just so you have all the info you can going in.
I would be nervous using glass containers for this experiment myself but that's up to you.