This may have already said, but I thought I’d put the word out there to caution others. My buddy who owns a Steam Deck OLED (my OLED LE is still shipping) said that there is a ribbon cable taped to the heatshield of the Deck OLED, and that you must be very careful because ribbon cables easily tear. There was also a deleted Reddit thread in which a 1TB OLED owner swapped their SSD with their LCD deck’s SSD, and did not receive their startup movie or exclusive keyboard. Be sure to login to Steam on the OLED to get your virtual items before swapping the SSD!
For the rewards… You can log out and log back in; you should receive the rewards then.
Device information and serial number is only sent during login, so if you already have a current session (from your old Deck), Steam hasn’t had the chance to know you are on a new device.