Oh my goodness that is scary!
We have this whole thing going on in our area where many especially with several children hold their kids back a year due to the challenging curriculum the schools now have in place. I knew nothing about this with my first child and there again it's a trend at least at the school my son goes to.
I sent my oldest at 5, birthday in March, and he did fine and is in honor's classes etc etc.
The second son with a May, did not and it was more I think a maturity issue and he seems to have more difficulty in language arts.
I ended up having to hold him back and bless his heart he still struggles at times and things just don't come as easy for him as they do the oldest.
With my daughter I didn't have a choice because of her October birthday and I feel good about her having that extra years. I think she is bright enough but also the maturity issue.
Then the youngest obviously will be 6 when he starts also and I think he follows Noah in his path with the speech issues etc.
It's all a real challenge that we work through just like everything else