Malay was the third language we had to take in addition to English & Chinese, it was a non examination subject; this lasted through secondary school years. Ministry Of Education removed the compulsory 3rd language subject later on, don't know when they did. The kids these days, don't learn Malay at all unless it is their "mother tongue". I don't know if those who too Malay as their mother tongue, which we did Chinese , had to take Chinese as a third language, I never asked. I went on after school & took a small course with a certificate in Malay language for commerce & formal letter writing. That means that many people of my era, were tri-limgual, multi-dialect & a smattering of other languages too , like knowing how to swear in many of them.
The knowledge of Malay, is useful, especially of one have to go to Malaysia or Indonesia often. Knowing Chinese dialects is useful too, if one is travelling to countries within SEA & even Asia & beyond.