The Bat-Signal never made much sense. It only works on a cloudy night! Although sometimes the comics have had it shine on the side of a skyscraper, but that kind of defeats the purpose of a searchlight; why not just put some kind of signal light on top of the skyscraper itself, like the colored lights they use on the Empire State Building to commemorate various things?
And Batman's always been on the cutting edge of technology. Maybe a searchlight signal was cutting-edge in the 1940s, but not in the 21st century. It makes sense that he'd have something like the Batwave, an AI agent that monitors police bands, news, and such for signs of criminal activity and alerts him electronically. I liked it because it added something new and believable to the mythos rather than just wallowing in nostalgia for the sake of nostalgia. Although the actual design of his Batwave pager was kind of silly, with a big Batman logo right there on the front of it. Not a good idea for a device that Bruce carries with him and pulls out of his pocket in the middle of crowds, as he was often shown doing.