Overview
In WWDC 2020 titled “The details of UI typography”, the presenter announces that webkit has now support for a new standard in using the San Francisco font with CSS.
font-family: system-ui /* SF pro */
font-family: ui-rounded /* SF Pro Rounded */
font-family: ui-serif /* New York */
font-family: ui-monospace /* SF Mono */
This is fantastic and I think this means that if you were previously using font-family: -apple-system you should consider updating that to system-ui or another option in order to get the latest.
More Resources
If you like to learn more about typography for ios, please check out superview.dev category on typography.