If you would like to request a new font be added to the Font Picker, you can contact Shopify Support and Gurus can file a feature request.
All latest theme versions now take advantage of Shopify's partnering with the Monotype font library which gives merchants free access to a wide variety of fonts!
An extensive, standardized list of typeface options is now available, with previews of the typeface visible within the 'Customize' settings editor found under Online Store > Themes > Customize > Theme Settings > Typography.
The best way to ensure you benefit from this wide font selection is to make sure that your theme is up to date! Learn how to update your theme here.