It appears that that move has increased enrollment in higher level math classes in high school: https://www.sfchronicle.com/education/article/SF-schools-mov...

See also some of the motivation behind the change: https://priceonomics.com/why-did-san-francisco-schools-stop-...

I would argue part of the problem with the American system is that trying to rush students through a rigid curriculum leaves the teachers no choice but to teach by rote memorization and cookie-cutter problems. Slowing down the curriculum is part (but not all) of the fix.

Still, whether or not this policy is good, it takes a lot of spin to turn "San Fransisco is starting algebra a year later" into "witnessing public schools take math out of the curriculum at elementary, middle and high schools", which is what you claimed.