benz

You can check the mechanic of the slow in wowhead. Shapeshifting should remove all slow with "ensnare" mechanic, and shouldn't remove slow with "daze" mechanic. You can see that most effects with a daze in tooltip actually use ensnare mechanic, such as rogue's Blade Twisting.

True daze with daze mechanic are the mob dismount daze, and spell such as lock's Aftermath.

ps: sorry for my english.