I received a letter from Mazda explaining that it might happen when the update came. Their fix was to bring it to the dealer and have them redo your presets for you. Nothing happened to mine though. Just do it yourself.
if it does it to the the aftermarket ones (which it does, i have one in my tacoma) then it's reasonable to assume it does it to the factory units. it's the worst thing about it i think....always hated when it updated and i had to reprogram everything. small price to pay i guess