Morbius and Blade actually have a history in the comics, and at one point Blade was bitten by Morbius, which gave him the ability to walk in the sunlight.
Jon Watts was led into talking about Morbius by We Got This Covered, which mentioned Morbius would be a cool villain.
Blade had teamed up with Spider-Man at that point, so who knows where a potential Spider-Man: Homecoming 2 plotline could go, especially if the movie decides to do the whole vampire angle.
However, he came up with the possibility of Blade popping in somewhere in the movie, presumably because Blade is a vampire and Dr. Michael Morbius dealt with a blood disease that turned him into a sort-of vampire.