It is true that new songs may be adventurous to dance to, but adventure is not the main thing dancers are after. In fact, most dancers do not like to dance to strange tunes with irregular and unpredictable beats, but prefer to dance to familiar and danceable songs with a somewhat novel arrangement. Familiar and danceable songs arouse their desire to dance because, like singing and playing music instruments, they do better when they know the songs. DJs should avoid extremist taste and take a balanced approach to serve the needs of most dancers.
I believe that in selecting music the DJ must first pay attention to the danceability of the songs. (See Tango Music and Its Danceability.) I am a fervent believer that only the best danceable songs should be played in the milonga, so fervent that I deleted all songs that are not suitable for dancing and only kept the very excellent, beautiful and danceable songs in my computer. The fact is, you don't need thousands of songs to dj a milonga. A three-hour milonga only contain 15 tandas or 60 songs. If you meticulously select 600 songs that are of the highest quality, you can play for ten milongas in a row without any repetition. It is the quality and not the quantity that counts.