Never ascribe to conspiracy, what can be explained by incompetence.
My theory, a Gay op fail.
Someone impersonated JJYS and booked him a consult and the clinic using his address etc. A sort of calling his bluff. The letter from the clinic was was delivered to LR by accident.
Keep in mind Canada Post hired reams of new temporary mail carriers to handle the massive increase in Covid related online Christmas shopping. Mistakes will happen.
Medical letters are not always clear what an appointment is for, due to the very issue of missed delivery. So it could speak of an appointment at the surgical center, but not be clear if it is a consult or surgery.