Your owner that you rent from receives your Name, Address, Email Address, and Phone number. They need these things to complete the reservation in your name.
Most Owners that Rent out through an agency have probably been vetted by the agency, at least to some degree, though I am unsure how much. Also, the agencies like to use owners services over and over. If an owner does a good job, they want to do it again. They probably keep some type of list themselves about whether the owner did everything in a courteous, timely manner and without mistakes. I don't know if they survey you, the Renter, so see what you thought about the service.
Most, if not all rental services require the owner to sign a contract. I do not know if they specify anywhere in the contract that the owner is not to contact you 'on the side' or contact you for any reason other than something directly related to the rental. But, I presume they do. And even if they didn't, it would be inappropriate to contact you to sell you Tuppperware or something. (Does Tupperware even still exist?) Anyway, it sounds like the owner contacted you for valid reasons. I know you aren't complaining, but you were surprised.
ANYTHING having to do with your reservation MUST go through the
DVC Member that owns those points. Disney will not even talk to you about anything. So, a good owner who is on the ball can be helpful.
The owner can schedule Disney's Magical Express. And help you purchase
Disney Dining Plan,
Travel Insurance, and can make any special requests you would like. Such as, "3rd Floor at Tokelau, near the elevator, and preferably on the west side of the building and near to the reservation of your friend who is staying in another room. And Bob is having a Birthday, and Carol just came back from a military deployment, so could you please note that."
None of these things are guaranteed, but it doesn't hurt to ask. If you have a lot of requests, a particular building, floor or near family and friends, then I would prioritize them and when the owner calls he should tell member services, "It is most important, if possible to get close to their Relative/Friends room. After that, if possible, they would both like to stay in Tokelau on the 3rd floor near an elevator." Or, whatever. Member services will write these down, along with any special instructions. They will give it a try, to see if they can fulfill them, but it very much depends on who is checking out, where the rooms open up and etc. That being said, I almost always have some type of request like this and I have ALWAYS been able to get my requests. If you are traveling with someone else, and they are staying in a different room then the most important request might be to have Member Services link the two reservations together, even if you are not requesting adjoining rooms. By the way, Poly is full of adjoining/connected rooms, so that one should be fairly easy there.
If you have made special requests, you should do the Online Check In thing, and do it about 5 days before you travel. Because starting about 4 days before you travel, somebody at Disney (quite likely NOT at the resort, so more specific requests can help) goes through the pile of reservations that have checked in,and compares them to the scheduled check-outs and tries to match up as many of your requests as possible. If you check in 3 days in advance, or less, you almost certainly will have lost that opportunity. If you wait until you arrive at the resort to make your special requests of the front desk people, they are VERY limited in what they can do, because they pretty much can only work with whichever rooms have not already been assigned.
Does any of this help?