It sounds like KATC may be fixing to do something similar to what KBMT is doing here.
They have re-mapped LD stations KUIL and K36ID to 12.3 (main HD channel) and 12.4 sub channel). So, depending on which ones you can receive (both ion my case) you can have 12.1, 12.2, 12.3, and 12.4 coming from at least 2 different stations or even possibly 12.1, 12.2, 12.3, 12.3, 12.4, and 12.4.(KUIL and K36ID carry the same simulcast programming).
KATC may be doing the same thing by mapping the LD station to show a 3.X channel number bringing all the programming under one umbrella so to speak.
But bewarned, this will cause problems for some TVs...