I can't see where anymore single decker routes would get converted to double deck operation, just simply as I can't see them investing in double decks on routes where you can just about get away with single deckers which cost less to run. I've been saying this for about the last two years in regards to everyone thinking that the Angel B5s would definitely be going on the 27 and sure enough I've been proven right on this one and considering how busy the 20/20A can get, they chose StreetLite's rather than going for double decker's, so because of these factors, I can't see them putting anymore B9's on the Red Kites. I could be proven wrong though... (I am aware the 47 got B9's in 2015 which was previously single deck operated - Volvo B7RLE's)

If I was wrong about the 27 getting the hybrids, my next theory would have been a frequency decrease from 12 minutes to 15 minute operation.