For fun, I went back to find my post that Amy quotes and it was from February 2013. Just about three years ago. At that point, we were only in 2A.
I've been so wrong on so many levels with this show, but I don't think they thought about Travis/Bay in 2013. I think they just used the current situation with Bay and Emmett and decided to throw Travis in there. But that's not all that surprising to me. I find that the longer a show goes on, the more random couplings you tend to find. Some of these are flash-in-the-pans, just filler, and I guess depending on writing changes and even audience response, some can stick.
Travis and Bay were definitely random. What I like to call the out of nowhere ships, which can be cool depending on certain factors. A couple I shipped really hard pre-Switched at birth and Bemmett was sort of OON. Meaning that while there was build up in the season where they got them together, there was no build up or foreshadowing in the preceding season. They hardly interacted and were with other people.
I guess it depends on the writing and the actors' chemistry.
Neither of those seem to be particularly strong with Bay/Travis at the moment.