Daniel - i've never done the study, so no data - but i don't believe a RC would result in longer microbial shelf life as a result of not incorporating ambient air. I know others believe otherwise.
Why do i think thusly? Your chocolate already has a micro load on it (meaning your chocolate, while likely food safe, is not sterile - it has more micro organisms on/in it than you think) - so they're already there. You can't load your RC in a vacuum, meaning that ambient micro organisma are going to be in your RC when you start it in addition to what went in with your ingredients. When you pull a vacuum, it's not going to pull those organisms out, and while the ganache may be mixed under a vacuum, when you open the unit you break the vacuum, and ambient air will rush back into the lower pressure areas of the ganace to equalize pressure.
My opinion only, no data to support it 8)