My wife and I talk about Star Wars a lot, but we had no idea we'd have so many conversations about Star Wars: The Force Awakens for months after its theatrical release. When we realized that the April 2016 DVD/Blu-ray release would not include a commentary track, we decided it'd be fun to put together a commentary of our own, based on the digital release from a few days prior.
We committed to the idea, bought recording equipment, watched the film twice, and recorded and edited all in the same weekend. There are a hundred things I'd do differently if we did it again, but I think it turned out OK.
(YouTube embeds are audio-only, but I didn't think it worth trying to distribute it another way.)
We did another fan commentary for Star Wars: Rogue One the following year. I think we felt we had less to say about it, but it was still fun to do, and I enjoyed trying to make it sound better.
No idea if this will be a trend. I guess it depends on how good the next few movies will be. :)