Yes that is the major potential problem with this type of mouse model in general. Mice are modified to have a condition that resembles something like alzheimer'

Yes that is the major potential problem with this type of mouse model in general. Mice are modified to have a condition that resembles something like alzheimer's disease and then treatments are tested, but there's no guarantee that the underlying disease is actually the same, so if the condition that is induced in the mice is just a symptom rather than the underlying cause of the human disease, or just superficially resembles it, the treatment may not actually be effective in humans.