People are a bit up in arms that BC may have been joking about his answer and waffling between John and Molly, but let’s be honest and admit that the question wasn’t really a fair one to ask him.
Don’t get me wrong; my first gut reaction at the idea that he may have been joking was one of disappointment. I’ve stressed about the whole thing a bit this morning, but I’ve thought it over now, and though so many of us (myself included) want to hear Ben say, “Oh, John is the only one Sherlock could be with, of course!” He just honestly can’t say that. It would put him in an awkward position with Mofftiss, who he has worked closely with for so long and who really came under fire for Johnlock not becoming canon in S4, and also, Ben has a ton of fans. Not all of them ship Johnlock. So therefore, no matter how he answered that question, he was going to hurt someone or stir up some crap. He couldn’t possibly give a serious answer to it. Even if he wasn’t joking, he at least had to sound like he was. He did the only thing he could, which was to give an answer that was a little vague.
I’m also not critcizing the person who asked the question; I don’t really blame them. I understand the temptation to ask. It’s a strong force.
I personally believe that, knowing the character he plays as well as he does, there’s no doubt Ben believes Sherlock and John should be together, if Sherlock becomes romantically involved with anyone. That’s just my two cents, though. You can see it in every acting choice he’s made throughout the series. That will just have to be our answer, because the looks he has exchanged on screen with Freeman are the things that launched a thousand fics.