I would say that Japanese has been moving away from using too many kanji in the last 70 years. Therefore, even though I would not say that a new kanji will never be invented for a new concept, I would say that it is extremely unlikely. In the past, when a new word came into the Japanese language, they would use existing kanji in a new combination, such as telephone = denwa = 電話 = electric speech. These two characters had existing as kanji well before the telephone was invented. Nowadays, it is likely that the new word will enter Japanese as a garaigo. For Blu-Ray discs, the Japanese usually say BD (ビーディー）or buru-rei (ブルーレイ）ディスク(disuku). For the word selfie, the Japanese either use the katakana セルフィー or the existing kanji in a new combination "self-picture-taking" 自分撮り/自撮り. No new kanji were invented for these new concepts.