Just picked up Rancho Notorious and Our Dancing Daughters and noticed that while both of them had plentiful chapter stops, there was no listing or summary of them in the menu. How long has this been going on - did I miss a discussion of this ?
The issue with Singin' in The Rain is that none of the venues TCM normally uses are capable of Dolby Vision or HDR presentations ( that I am aware of ) so it's entirely possible that aside from the Dolby/HDR grading for the upcoming 4K release, the original files are not any different in regular...
I'm sure it's making a difference. Twilight Time ran into the same problem and I bet Criterion wishes they could pull back from the 50% off promos multiple times a year.