It's somewhat common for a version of a type family available at Adobe Fonts to have a limited selection of styles rather than the complete family. The situation varies from one typeface to the next. Many type families at Adobe Fonts are complete. Some are missing styles. For instance the recent addition of Helvetica Neue to Adobe Fonts has only 14 styles; the complete family has 59 styles. The Adobe Fonts version of Mislab is a "standard" version; the "pro" version sold by Typofonderie has a larger character set.
The situation comes down to decisions made by the companies who have the distribution rights to those typefaces.
In the case of Josefin Sans, the Extra Light and Medium styles are only available in the Google Fonts version (which can be downloaded for free). Google Fonts also has a variable version of Josefin Sans.