Stories are just stories, I frequented the beta forums every single day and I saw no posts about people losing their entire saves, unless the bug had existed before the DLC.
I'll say this:
This is the
least bug filled DLC Bethesda has ever made, and I bug tested extensively. And that was the BETA. It should most likely have less bugs than the beta did upon release, assuming all goes well. As a general rule of thumb, I always make back up saves regardless of the company's reputation, though.
Besides, Bethesda has buggy games because their games are so big, not because they're a bad company or anything.
