This is what I received from WDW Staff when I sent the question:

Thank you for contacting the Walt Disney World Resort.

While we sincerely appreciate your interest, tipping is not mandatory.
However, if you would like to show your gratitude for great service, a
tip would be welcome.

If you have questions or need further assistance, feel free to contact
us.

I think that answers the question about tipping. It is all up to the individual. I pay my housekeeper to clean up after my family, so I would leave a little something for Mousekeeping as well. Also, if I think the service was inadequate, I would let the front desk know as well.