Not if you consider it a post-mortem of the development. When the project is done, development is dead (cue: pedantic comment on product life cycle). So it's not technically a post-mortem of the game, but a post mortem of the development process of the game. The post-mortem's at Games Developer/Gamasutra are typically for commercial games, and often offer a retrospective of launch and relative popularity as well.

Someone can die, but not have been a failure in life. I've always taken post-mortem blogs to mean "We're not working on this anymore. Here's what we learned during the time we did." The reason for a project ending is often failure, but it doesn't have to be. I've seen several post-mortems about successful projects, they're just not nearly as common as the failures.

Perhaps "debriefing" would work?

Merriam Webster provides a second definition: "following the event".

Post-mortem is widely used to refer to analysis of a completed project, failed or otherwise.