Congrats to your son on the good start. 15:47 on a legit xc course is very respectable. As @lubbub says, xc times are viewed as unreliable. Placing well in a big meet is probably more meaningful, and track times are the gold standard. Still, I would think most D1 coaches would love to chat with your son even if as a potential walk on. But if your son is hoping for significant scholarship money, just make sure he understands the track/ xc scholarship situation for boys. 12 scholarships max for track/xc combined. There are quite a few outstanding HS distance runners on 10%, or even no scholarship. Also, have him think about what he wants running in college to be like for him. D1 can be intense, time consuming, and at his level in a good program may involve very little racing. D3 can be more like a HS experience, and his times may open some D3 admissions doors if that’s an issue. Having said all that, college coaches like late bloomers if they’ve been undertrained.