here's a thought i just had about kira's newtype abilities.
i remember that in a flashback mwu's father approached the scientist who wanted to create the ultimate coordinator(kira) and had asked the scientist to clone him which resulted in rau. well since the scientist did clone mwu's father he would need his genetic information right. so what if he found a gene that resulted in newtype abilities in mwu's family, hw would've wanted to implant that into the kira because he was going to be the ultimate coordinator.
during gundam seed the "ping" would only occur when mwu and rau were around each other, so perphaps they can only sense others who have the same type gene. in one episode when they were fighting in the interior of a colony it pinged when rau sensed kira, so that could mean that he shares some genetic similarity with rau and mwu. and i think that's why in seed destiny kira was able to sense neo during the battle in episode 23 and in 32. and it would also pertain to neo and rey during their fight at the beginning of the series, sharing some genetic similarities.