I realize I'm stating the obvious to most here, but just in case some people are going through this right now:

In many places it's very easy to get around this by doing private kindergarten.

My parents did this with me and we did it with one of our kids. In an ideal world there would be a discretionary process but if you aren't up to fighting a battle and you can swing one year of private school financially, it gets the job done.

This is only a super easy fix is your child is fairly close to the cut-off date. Otherwise it may still be iffy to convince a private school to accept a young kindergartener.