They should make it clearer whether the search engine actually takes account of whether someone has passed a course/courses.
And by successfully passing the course’s final quiz, you will showcase your new capabilities.
Therefore, by successfully completing a course, you’re also likely to gain more visibility in the Fiverr marketplace
The “likely” makes it sound like it’s just a side effect - that more people may want to buy the gig and therefore that in turn may increase your visibility in search because of selling more gigs.
But it also says (twice):
Passing a course is only one of many factors that can impact your ranking on Fiverr.
So they should clarify if the search engine takes account of it or if it’s just a side effect (more sales because of the course=better ranking).