Is it an appartment building where this owner owns the whole building? Or is it an individual who owns your unit and its technically a condo?
If it's an apartment building and he owns all the units it may be as others mentioned, he may be wanting to stay on top of it etc. etc. Use it for tax deductibles etc.
If it is an individual it could be for tax reasons, it could also be for a totally random and unpredictable reason, we've had owners for some of the properties we manage ask if they can keep one of the utility bills in their names because they use the address for their kids school or so they can attend that cities Boy and Girls Club because it's closer to their work. There may be an atvantage to having that address for getting car insurance, there may be a discount card for all the golf courses in the city if you are a resident, you may only be able to get a neighborhood parking pass to park in the area if you show proof of address. This of course is only plausible if his home address is a different zip code.
Have you asked him? I would first ask. Well not first, first I would look at the lease agreement, if it is a 1 year lease and not month to month he cannot ask you to change anything if not specified in the lease. If it is nwo month to month I would ask him point blank.
I would not resort to assuming it is something fishy if he has not set off any slime-ball alarms in your head over the last 3 years. Heck he could have gotten (maybe not even good) advice from an accountant, lawyer, property manager etc. I don't know if he is a professional landlord or not.
Refer to lease, and ask him why.