I'm assuming the rep was wrong..from Marriot's terms and conditions, even clearer explanation:

Not all Points activities help maintain active status in the Rewards Programs. The following activities do not count toward maintaining an active status in the Rewards Programs:

-the transfer of points from a Member’s Rewards Program account to their SPG Program account, or the transfer of points from a Member’s SPG Program account to their Marriott Rewards account. Note that following the transfer of points across accounts, the points expiration policy of the account to which the points were transferred will apply to such points.

Edit: The problem I have though is my account website is totally wrong then on when my points expire. They should clean this up so there is no confusion. When someone sees an expiration date of their points on their Marriot account's website, they should be confident that info is correct.