Jones went into college and was recruited as a WR. He could easily have started at WR at Arkansas if he wanted to. So, while it may take him a while in running routes, he has the discipline to get the job done. Route running is a key - but the real key to that is discipline, training, and athletic ability.
Jones is not just an athlete, however, he has great football instincts.
WR is definitely his position - he doesn't have the bulk or power to play TE.
The comparison to McCaffrey was not unfair - b/c it noted Jones would be a faster McCaffrey. It is similar in that both have tall, lanky, athletic bodies. All Jones will need is a year or two at WR, plus some luck in remaining healthy, and he'll be a big time playmaker in the NFL.