I read this recently:

A handful of the most competitive schools, such as Harvard University and Princeton University, still require three Subject tests in addition to the three sections of the SAT. It is important to consult the school's website to find out more information about Subject test requirements.

Is this still true?

When in doubt, check it out.

I don't think there is a blanket rule with those extra sections so it is best to look at websites or catalogs to see what will be required.