I still, personally, found the ending of Glass to be wildly underwhelming. The introduction of the secret society raised far more questions than the movie had answers to, and the cliffhanger ending was unsatisfactory. Yes, Elijah managed to get the footage released — with the help from Casey (Anya Taylor-Joy), Joseph Dunn (Spencer Treat Clarke) and Mrs. Price (Charlayne Woodard). But what will it matter? Will the people believe? Or will they shrug it off? Elijah’s mission might be for naught.
Article source: https://www.cinemablend.com/news/2465486/m-night-shyamalan-explains-his-intentions-with-the-glass-ending