They are not missing.
Within the last year or two many cameras do their own lens corrections before writing the JPG or even displaying the image on the back of the camera or in the electronic view finder, so Adobe does the same thing: the lens profiles are built into the camera raw engine and always applied. It’s confusing because cameras didn’t used to do this and Adobe didn’t used to do this, so we have the situation of older cameras having lens profiles you had to select from the dropdown lists, while newer cameras don’t require this. Of course removable-lens cameras still have this situation, but many/most recent P&S cameras have built-in lens corrections.
The Camera Raw plug-in for Photoshop actually indicates when a built-in profile is being used, but LR does not, yet.