I homeschooled my dyslexic now 17 year old son starting when he was 7. His issues have been remediated probably as much as is possible. He reads very well, he is able to write reasonably coherent papers that are good enough to earn As in his college composition class. When tested by professionals that understand gifted dyslexics, it's possible to see that the deficits are still there, even though he seems to function very well. For example, his processing speed is at the 1st percentile (it was explained to me that this means he takes about twice as long to do the types of tasks required on processing speed tests as an average person his age). So even though his (accommodated) achievement scores are through the roof, he qualifies for accommodations at school and with the College Board.
If your son were to go to school in the future, if he has a dyslexia diagnosis, he will probably be given accommodations without any issues, but he likely wouldn't qualify for an IEP if his achievement is in the average range (which starts at the 16th percentile here).