I read this and it does not say he shot down rumors of a justice league live action film despite that being stated in the title. This is all it has to say regarding Justice League:

DC announced over the weekend a Justice League animated film that would be released in 2024 and it’s based on Crisis on Infinite Earths. Many deduced that this could be the basis of a possible live-action film by Gunn. However, Gunn shot down the rumor by replying to a fan with a simple “No,” on Threads.

It simply states there is no Justice League film based on Crisis on Infinite Earths coming. This article mentions 3 heroes—Guy Gardner, Hawkgirl and Mister Terrific—but fails to mention they also added Anthony Carrigan as Metamorpho to the cast as well. Feels like the author kind of half-assed this. Honestly though, whether the movie is labeled as such or not, once you reach a certain number of DC heroes teaming up it becomes a Justice League film by default.