California is slowly moving that direction by expanding out DK. Our twins got to attend last year because of the new cutoff. And our local elementary school added a 2nd DK class this year due to the continued expansion (before they only had 1).

There definitely does seem to be a learning curve involved here. They try to teach DK to K standards because there are no other standards. Which is just unrealistic, especially as you start accepting nearly newly 4 year olds.