Well physical prices need to be sent somewhere, so yeah in case you win a physical price these infos are required.
But as far as I know in Germany you can also give the adress of an anomynos postbox or after winning contact the team and talk about other possible ways of distribution.
I did win the "spot the difference"-contest earlier this year (what was it, spring?) and so I did get the request for my name and adress after the fact. (oddly enough a request for my phone-number followed after I had given those, which I refused to give, which led to me being given the message that if I wasn't willing to give my phone-number, I might not receive the prize!)
I still refused ("OK, then no goody bag, there are limits after all") so you MIGHT get an idea why I am suspicious, AND claim participating is NOT FREE...
In this contest, a participant has to approve up-front to gave name and adress (instead of after winning anything) and I can only hope that RN has decided after the earlier contest that a phone-number really is not necessary to send any package over.
As you may see and/or admit: my remark about participating being not completely free comes from experience in dealing with these things with you (plural), not from some vague imagination.
NB: my goody bag from the spring-contest arrived just fine, and without delay, despite me not having given my telephone number to RN.
Thanks for that.