Questions: Guy's Behavior

I started uni very recently and before it started, i had become friends with a guy who's going to the same department as mine on social media. We exchanged texts daily and the exchange was playful and fun. He even said we'd be inseparable close friends by graduation and i expected so too. but unfortunately, we didn't get into the same class, which virtually means we won't have contact with each other even on the same campus because classes are completely separate. Still, last week when uni started, we finally met for an info session at uni and went to lunch together before that. I enjoyed chatting with him because it was very easy to talk to him and i assumed he did too, but later that day when I texted him and suggested that we hang out again sometime soon after class, he texted me back and said not anytime soon bc he'll be busy with classes and other activities, strangely also adding that he would prefer to hang out in a group next time even if there's next time. i'm sure he's not in a relationship and i never suggested anything romantic and i genuinely just want to hang out with him again because it was fun chatting with him. since then, his replies got very slowly and much shorter. On top of that, i asked him this week if he'd like to go to an interesting uni event this week after class with me and when he finally replied he shortly just said he'd take a rain check (as his classes end before noon that day and the event is in the evening) and suggested i ask someone else particularly in my class out. I can't help feeling he's no longer interested in maitaining our still new friendship. and it's realistically very likely to just fizzle out as i don't see him at uni and texting is pretty much the only communication between us. Should i just let it naturally fade away without trying to keep the texting going and just forget about him or try to keep in touch with him by still sending him messages?