Really what it boils down to is they couldn't possibly stomach having a strong black character have a basic premise of being John Wick with vampires. With no comedy, love interest or tongue in cheek humor.
So they tried valiantly to make every other movie except the one that people wanted to see. And because of the lead actor refusing to bend to it and because of the quality of the or lack thereof that was being produced it wouldn't work
And I do agree that Sinners really put them in a bad spot because it was so successful. Now they're outta excuses.
They never really wanted to make the movie in the first place.
Blade is literally one of the easiest movies to make because not only is the basic premise simple,
the budget can be small and there's a previous film in 1998 that is the gold standard what you need to do.
These are all excuses because they didn't want to make the movie in the first place