Glenn Close is a wonderful actress. When she opened in the role on Broadway in '94, she was an appropriate 47 years of age, gave a brilliant performance, and deservedly won the Tony. Unfortunately she only stayed with the role for 8 months and I wasn't able to make it to New York to catch her in it. Instead I went to Toronto and saw Diahann Carroll, who also was quite effective.
When Close reprised the role in the 2017 revival, I built a trip around her show so that I could experience her performance on stage. I was not disappointed and was easily able to suspend any disbelief I may have had about her playing Norma at age 70.
While I don't think it wise for Close at 74 to play Norma in a film version, I admire her chutzpah for trying to get investors to come up with the financing. I don't think it will happen, but who knows? We'll just have to wait and see.