font-display is getting some attention, although still experimental in many browsers.

https://css-tricks.com/font-display-masses/

Chrome/Canary, Opera and Firefox have it although it is disabled by default. Hope it comes out soon.

This leaves Google Fonts to implement it. Since it should be included with the @font-face declaration, Google Fonts can allow passing of a parameter such as "&display=swap" in the URL which creates css files with a declaration:

font-display: swap;

in the css file.

Are developers of Google Fonts thinking about it?