Ever since Season 1 HBO have released a "Inside the Episode" video that gives some insight into the episode. They also released other shorts and clips of actors and people involved in the show to give their thoughts on it. As of Season 7 they also added a longer "Game Revealed" video which was like the "Inside the Episode" but also some behind the scenes footage and "how they did it" parts.
These have been quite helpful in revealing character motivations and why some things were done as they were.
However, neither have been released for the final episode. There is a lot here that could actually do with being explaining or clarifying, where did Drogon go? Why didn't Grey Worm kill Jon straight away? How did they find out Jon did it? Etc. Just look at the questions on here about the last episode to get an idea on it.
Why weren't these videos released for the final episode? Usually they are released along with the episode or a few hours later but days later they still aren't here so I imagine they won't be at all.
We do have "The Last Watch" documentary coming out shortly but that is for the entirety of Season 8 per my understanding and all the other episodes had "Inside the Episode" and "Game Revealed" videos released. So that shouldn't affect whether or not they wanted to release them.
I am looking for answers from the people involved with the show not theories or speculation as to why, so interviews or the like would be helpful.