Denise L, ... "I don't want to mess up my timestamp by calling, but I do want to verify my requests from 10 months ago."
One of the reasons Starwood asks for a verification of an email address is to send the owner making the reservation an email confirmation of the reservation. If you are worried about your request for the reservation itself, you should have that confirmation sent by email. Print it and bring it along with you. If you don't have it, call and ask that another be emailed. I have mistakenly erased an emailed confirmation, had to call again to get another email sent and it has never seemed to affect the preferences for my reservation.
If the requests you wish to verify are your preferences on room location (building, high or low, handicap room, type of view, etc.), those matters for the reservation are not guaranteed by Starwood. They are placed in the "notes" section of the reservation. To avoid arguments at check-in about any "right" to or promise of preference being filled, they do not even show on the confirmation. The preferences should only be viewed by you as suggestions.
If you are calling to verify that what you said at the time the reservation was booked is in the "notes" section of the booking, I would think that calling and asking to have your preferences in the "notes" section read back to you would not affect your time stamp.
However, if you are calling to change a preference, you forgot to state any preferences then or you find that the preferences are not there and have to be added to the "notes" section

, I am afraid that you could affect your time stamp by making a change to the "notes" section. And, I have no actual knowledge, but it seems logical the Starwood computer system changes the time stamp automatically if any of the data fields in the reservation are changed. (Another way of looking at time stamps, is that they are probably a record of the last time the database for the reservation was changed, not merely viewed by calling up the record of the reservation.)
However, I believe there is a misconception that the time stamp controls all assignments over all categories of reservation. I have not found that to be the case.
I am fairly sure that ownership at the resort affects home resort reservations. I am pretty sure that resort owners using a home resort week have their preferences filled first (there is no privilege to ask for an "upgraded" view preference at Maui for home resort reservations. You get the view you purchased.). Next, I am pretty sure (from experience) that Starwood Elites have their preferences filled next. Other non-Elite Starwood SVN traders have the privilege to state preferences and those are filled next.
SPG renters and II traders have no privilege to even ask for preferences. They tend to get whatever rooms are left over after filling the reservations where a preference has been placed in the "notes" field. It would not surprise me if Starwood gives SPG renters priority over II traders - but I just have no way of knowing.
(A standard TUG recommendation is for SPG renters and II traders to call the resort and ask for something a couple of weeks in advance of arrival. Since the reservation detail in the central Orlando computer only goes to the resort shortly before the dates of arrival, I'm not sure how effective such a recommendation is because there may be no database that can be accessed and updated by the resort to record the SPG or II preference until after the call to the resort is made.)
What I do know is that within these broad categories of reservation, time stamp is a factor taken into account. I also know that the resort reservations staff tries to match all preferences so that the preferences of each guest is fulfilled as far as is practically possible.
But, when the resort is full, someone has to have the units with a parking lot view, or the units closer to the elevator or farther from the pool, or a handicapped unit they didn't ask for, or the units with a lower view that may be blocked by vegetation. And, remember, these people in reservations are trying to please everybody and there is no "right" to a preference. Even so, they know every satisfied guest is a potential repeat customer. Every unsatisfied guest (even a home resort owner) has options like SVN trading or II to go elsewhere.
Since you say you stated your preferences when you made the reservation, call Owners Services and ask that time stamp not be changed but that the preferences in the "notes" be read back to you. I have also gotten antsy and done that. It did not seem to affect the filling of my preferences. GLTY! ... eom