The article said that as well. Although, oddly, it says "when they're in trouble.."
>New aircraft must broadcast their locations every minute when they’re in trouble, but only from January 2021. A gradual tightening of requirements starts in November, when airlines must track planes every 15 minutes under regulations adopted by the United Nations’ International Civil Aviation Organization.
There's already in many areas a requirement for aeroplanes to provide ADS-C via Inmarsat satellite updates at 15 minute intervals so that makes it easy to regulate (just increased cost making it global) https://www.aviationtoday.com/2015/09/25/ads-c-makes-increas...
>New aircraft must broadcast their locations every minute when they’re in trouble, but only from January 2021. A gradual tightening of requirements starts in November, when airlines must track planes every 15 minutes under regulations adopted by the United Nations’ International Civil Aviation Organization.