Flash floods are a bigger concern than the slipperyness of wet slickrock.....it's actually very grippy, like driving on 80 grit sandpaper.
If sand gets washed over the slickrock, it can be slippery where you cross a wash. There are trails that we may have to deviate from if the weather becomes an issue, but there will be plenty of alternate choices to fill in........and the bonus of a desert rainstorm.......there are some really cool waterfalls that appear out of nowhere as water spills off the mesa. AT tread tires work very well in Moab, MT's are good too, siping would help an MT grip slightly better, but I'd save your money.
Pray for sun, prepare for rain.