There is no big mystery…just ask. It always surprises me that gossip can take flight so easily in the workplace. Why is no one asking the question(s) that can clear gossip up? Why do we not ask direct questions when we have concerns or fears? Is it because it is easier to remain in the comfort of limbo rather than risk having to take action? Perhaps in some cases this applies.
There seems to be a propensity to gravitate towards the realm of not asking especially when it comes to bosses. Here is a helpful tip, your boss is not the great and powerful Oz. He/She does not require you take a long journey down the yellow brick road, etc. Given that perhaps it might be easier to have a direct conversation and resolve any questions or issue you may have. Just walk down the hall and do it, or schedule some time to do it.
Seriously, which do you think your boss would prefer…you engaging in killing time not knowing and worrying or gossiping, or having a conversation that will leave you more productive and save everyone time and trouble? Yep, you know the answer. Go do it.