In Skype for business when someone comes online while being out of office you can see that they are online (large green dot and small purple one). In Teams you can only see the out of office status with no apparent way to tell if they are online or offline.

I think you should fix this so that the out of office is a bit separate from online/offline status as OoO could just mean you are working from home. If this is intentional I think it should be solved in a different way by adding the concept of invisible status for when you do not want to appear online.