As vicki_c said, you are talking about a transfer of points. Transferred points can be added to a contract only if they exactly match the resort and UY of that contract. In this case only, you will see the transferred points online because they can be added to your point balance since they are an exact match to your own points. For all other cases (same resort, different UY or different resort, same UY or different resort and different UY) the points are tracked separately somehow (probably manually). MS can see them but they will not be visible to you when you look at your account online. If they are the same resort and the correct UY for your travel dates, you can combine them with your own points to book 11 months out. If they are from a different resort, you can use them to book that resort 11 months out or you can combine them with your own points to book anywhere 7 months out.
As mentioned, unless the points are the same resort and UY as one of your own contracts, you won't see the transferred points in your account. This can be an issue if you are trying to book a high demand resort or room type because you won't be able to use them to book online when the booking window opens at 8am eastern time. You will have to wait until 9am and call MS to make the reservation. For certain rooms at busy times of the year, that hour can make the difference between getting the room you want and missing out.