Read my above post to answer that.
What I read was this "There are certainly differences between the seven documented forms of lycanthropy in Tamriel, but more similarities.
In Black Marsh and southern Morrowind, werecrocodiles stalk the swamps. Black Marsh also shares with the Imperial Province and the wetter parts of Elsweyr the vile presence of werelions. Valenwood's werevultures are not found in any other province. The wereboar has found both the climates of High Rock and Hammerfell amenable. As I mentioned before, the werebear is the most common lycanthrope in Skyrim, and is also found in the northern parts of High Rock, the Imperial Province, and Morrowind. The werewolf can be found in every province."
The biggest word being DOCUMENTED
also "The seventh lycanthrope, which I have never seen but my trusted peers have assured me exists, is a wereshark that roams the oceans around Tamriel."
Which implies he has actually SEEN all the others.
I'm not convinced that this particular lore about nobody ever seeing a werebear exists.