Looking at it having recently stopped shooting film, there aren’t many holes in the Kodak product line.
In C41 there is Ektar 100 and then Portra 160/400/800. Replacing Portra 800 with a 1600/3200 version would fill a hole (400 handles 800 well enough), and maybe adding a 400 Ektar might make sense.
In BW there is TMax 100/400/3200 and Tri-X 320/400. A slow speed traditional grain film could fit in.
In E6, a 400 speed slide film would be nice.
With two more colour films; 400 Ektar and 400 E6, and one more BW film; 100 Tri-X style film the range would have virtually no holes. I don’t think Ilford has any holes in their lineup.
Of all those, only one would get me back into film, a 400 E6. If they released that I’d buy another film camera.