I don't think so, completely different geometries there. Winglets on that diffuser (seen on Sauber and Haas this year of course) were used to accelerate air right behind diffuser, to help it with "pumping out" the air under the car. Just like air on bottom of race car wings accelerates, so it does on these multiple winglets. Other than that, it raises pressure on top side of diffuser a bit, creating slightly more downforce that way too.
And of course, it directs air where the team wants it to go.
And they call it a stall. A STALL!