Yes, there are.
If you water the nest on a regular basis, which is necessary for most species, it will get moldy pretty fast.
This won't happen if you keep a species like Camponotus ligniperdus in it as they don't need a moist nest at all. However, they can easily chew through the cork. These are only 2 downsides of probably a few more. To keep Camponotus ligniperdus in it, just use an aluminum frame or similar. I can't suggest it for any species that need moist nest areas.