Mana, I take away quite a different message from that article. Combining the data from the U.S. and Norway, the evidence seems to suggest that there is no negative effect of being in a program that is nurturing, play-based, emphasizes social-emotional skills and fosters attachment of the child to a particular teacher.

(What has skewed the interpretations is the use of socio-economic status of the family as a proxy for the quality of the program. Hence the claim that "even high quality" programs have negative effects, without looking more carefully at differences between types of programs.)