I swiped right on him over the holidays while he was in my town visiting his family, and he matched with me after he flew back home (side bar: what's up with that? was he just bored?).

I can assure you that your swipe wasn't on the top of his list of things to get to.

I'm not one to beat around the bush, so after about 3 weeks of this, I ask him (not rhetorically) what he thinks is going on here. He replies, "I have no expectations. It's fun to text but I like talking to you." <--- WTF DOES THAT MEAN?!

It means EXACTLY what it says. No expectations.

I've hinted at him calling me by saying: it'd be nice to talk to him on the phone, and I wonder what his voice sounds like.

You've been texting for 3 weeks and he hasn't offered to call you? LOL. He ain't interested in you. Please refer to my previous comment above.