Of course digital movie tech can be B&W.
A black-and-white_film has a certain type of style and texture to it. Thus, 21st century black-and-white_films still have an audience. There seems to be no slowing down of_black-and-white_productions. So its no surprise that ZS will offer a black-and-white version of his cut.
"Zack Snyder's Justice League: Justice is Gray is officially coming to HBO Max. The black & white edition of the movie is Snyder's definitive version." https://screenrant.com/zack-snyder-justice-league-gray-black-white-hbo-max
https://www.vulture.com/article/modern-black-and-white-movies-directors-mank.html
https://variety.com/lists/black-and-white-films-best-movies-mank
https://screencrush.com/best-modern-black-and-white-movies
https://filmdaily.co/obsessions/best-modern-black-and-white-movies
https://birthmoviesdeath.com/2013/09/16/true-movie-magic-how-the-wizard-of-oz-went-from-black-white-to-color This might be the best example for a movie to partly be B&W and then transition into color for its spectacular cinematic effects. https://filmschoolrejects.com/the-wizard-of-oz-at-75-why-we-can-t-take-the-black-and-white-to-color-gimmick-for-granted-8485ecb537bc
https://oz.fandom.com/wiki/Technicolor , https://www.youtube.com/watch?v=YWFHeDcVNiw
https://thedigitallabyrinth.blogspot.com/search?q=Justice+League+Snyder+Cut
https://thedigitallabyrinth.blogspot.com/search?q=The+Wizard+of+Oz
