While I would love to see you two duke it out, I'm going to jump in here. My experience with the teen club DJ's (and believe me, its extensive), has been that the cruise line does provide a subscription service for them to use. I've seen DJ's (more than once) passing around the Billboard Hot 100 for requests (as old as maybe a week, but who is going to complain about a week old music?). I have also been inside a DJ booth while he was mixing - I've seen Promo CD's as well. I would find it rather hard to believe that any DJ is expected to go to work and not be given the means by which to do his work, especially at sea, where availability of things is very limited.
Now, I've also seen Teen hosts who are not great DJ's throwing music on a playlist on an Xbox 360 or PS3. Even then, the music is not old either - might be behind a week or two, but given the time it takes to ship and deliver something to a ship thats only in a US port once a week, sometimes less, its not surprising.
As for the professionalism, I would lean to agree with Ryan - it is unprofessional to provide a DJ with music, especially when he/she's up there doing their own thing. It is also very illegal if you do not own the distribution rights to the songs and the DJ plays them in a commercial setting.
And just FYI, I hear the electric slide perhaps twice all cruise once in the Teen Club, and once on the Deck Party.