I booked a reservation with a European Hilton while I was still Silver and by the time I stayed there I was already Diamond. The check in staff only saw the Silver status, which I did not immediately realize. It was only after I unpacked and asked about Lounge access did the topic come up. They insisted on seeing my Diamond HH card, and then proceeded to upgrade me to the Executive floor. I didn't even want the upgrade since I had unpacked (I only wanted Lounge access), but it was back in the day when only those on Exec floors got Lounge access so I had to move.

So, moral of my story, it doesn't hurt to mention your status at check in, especially if it has changed from when you booked.