Was not the case for me.
Have had my K Bank one for approx 15 yrs - zero savings required.
My BKK Bank one for 3 years - Zero savings required... infact I had not yet received my first payslip when it was approved.
My amex - 2 yrs, not sure if savings required or not but I did have a reasonable amount in my BKK Bank savings account when I applied for it.