I think it all depends on the individual kids skill level, interest, and his goals. My kids have dealt with this issue before, and they decided not to wrestle middle school in their last year of middle school because they felt bored, unchallenged, and actually felt as if they would not advance in the sport by wrestling middle school. I was very supportive of their decision and offered an alternative season involving practicing at different clubs as well as working with them individually and competing at competitive tournaments. Well the decision was the best decision that could have been made for their particular situation, as the following year they were well ahead of their rivals when they stepped on the mat and wrestled them in high school.
Again, this is possible when a child has someone that can take him to various clubs and places to practice, as well as take him to selected competitive tournaments. Not all situations are the same, nor not all kids are afforded the same opportunities. But if a highly talented kid who does not feel challenged in middle school wrestling has the opportunity to continue to grow technically and competitively, and has the support of a parent, coach, brother, or other mentor, then yes, I would recommend him to skip middle school wrestling and take a different route if that means he will be happier and experience a more enjoyable wrestling experience.