I just checked the CFA Institute website. They say you must have a "bachelor's (or equivalent) degree or be in the final year" of one OR four year work experience (in any field) OR combined education + work experience of four years.

I think what you are saying is true for using the designation (becoming a chartered holder)--you need to have the practical experience of four years.

CFA Enrolment eligibility : https://www.cfainstitute.org/programs/cfaprogram/register/Pa...

Experience required : https://www.cfainstitute.org/community/membership/process/Pa...