Yes it would still be subject to atrophy. Ever had a cast for a broken arm/leg? when you don't use a limb/set of muscles for a long time, they lose mass. This is the same as long term(bed confined) patients of chronic diseases/coma patients.
This statement from an article from the US National Library of Medicine states that after 10 days, atrophy can be seen:
It is recognized that muscle atrophy during prolonged (>10 days) disuse is >brought about primarily by declines in post-absorptive and post-prandial muscle >protein synthesis rates, without a clear contribution from changes in muscle >protein breakdown
If thats showing after 10 days... 6 months will have horrific effects.
IF there was some sort of intravenous/nutritional input into the person, maintaining a sort of dietary equilibrium where muscles are not being broken down to move important nutrients to where its needed most, atrophy will still occur. The human body is very good at adapting to a situation. Thats why exercise needs to be pretty much consistent, or else you lose what you've gained within a week or two.
As the person is in 'hibernation' there won't be much movement so any anabolic enzymes (the little critters that help build/maintain muscle mass) will break down. Maybe any tech that you consider should include this as part of the process, but more information on the technology needs included.
Best I can do :D