If they didn't then they'd have to be setting up whole floors of Call Centre staff just to deal with the resulting mess! And again, as you are wondering... 'but was just wondering if others who upgraded to VP13 got one.' Why wouldn't they, if they HADN'T already got the product already AND its own SERIAL.
Cheers Grazie. I upgraded from SVP 12 to 13 and i also received new serial numbers for: Vegas Pro 13 Upgrade (Download) Serial Number: xxx DVD Architect Pro 6 (Download) Serial Number: xxx iZotope Nectar Elements Serial Number: xxx All the email said about Video Essentials VI was: Your Vegas Pro 13 purchase includes Video Essentials VI. Now upgrade to eFX and get all the tools you need to accelerate your workflow. This diverse and balanced series includes 70 plug-ins and more than 700 presets. Vegas Pro 13 users save 25% by visiting: n.b. No serial number was supplied.
When I upgraded from 11 to 12 that included Titler Pro complete with a serial number. Likewise when I went from 10 to 11. So I think the OP has a point.