yes & no. if it's too humid your substrate might get damp causing scale rot. or if you have any type of wood there's a chance of it getting moldy. however, if your ball python is close to shedding, bumping the humidity up is always a good idea.
if your humidity is always 80-90% you might want to lower it. you can get a dehumidifier or a much simpler thing to do would be to get a small fan and put it over the screen of the snake's cage to suck the humidity out. having a light on the cage will also decrease the humidity.
I have my kids in Sterilite tubs, so a fan is not practical. I guess I'm more worried the high humidity is an indication of stagnant air.
My quick fix is burning more ventilation holes...I think I answered my own query.