You may have heard already, but they raised the volcano alert level from1/5 up to 2/5. It still seems fairly safe. Our guest houses should be ok, unless there was a major eruption. They are not warning people out of Hakone, but just around the Owakudani area:
Personally, I am not very concerned. Our guest houses are far from Owakudani. I will teach at one of them each week.
If they suspected a major eruption, they would close everything down. They haven’t.