-(Interviewer points out how multiple endings and loops are common in video games, and asks what Urobuchi thinks, as a game writer): They're appropriate since battle royales in general are very game-like.
-(Interviewer asks why he thinks loop stuff like Ryuuki, Haruhi and Higurashi were popular in the 00s): It's something anyone who plays video games will imagine. The writer of All You Need Is Kill said he got his idea from video games' save/load functions, and everyone has died in a game and started over with the knowledge of what's coming next. Everyone probably thought of turning that into a proper story at the same time.
-(Interviewer asks why Madoka was a loop): He came up with Homura first as a character who, while silent, stays by Madoka's side and knows everything. The best way to get that to fit was a loop. He wanted to make a sort of betrayal, where this mysterious person plotting stuff in the background you can't seem to trust turns out to be the person who was thinking of the protagonist the most all along. So the loop was just to justify Homura's actions.
-Ryuuki was in 2002 and he was surprised that they did a loop at such an early point, and in a Kamen Rider.