Jai, that's really awesome! I'm really happy for you and your son that you've had such a great turnaround. A good and supportive principal is the best thing a school can having going for it, imo.

I would still follow up with the eval just because you never know how the future will go (what if the principal leaves next year or you end up with a new teacher who isn't so awesome? sometimes having a paper trail is helpful).