Changesets seem like a UX nightmare. While I understand the motivation, the complexity of version control today is mind boggling.

We have a working copy, index, commits, branches, remotes, pull requests - all of these come into play when proposing even the simplest change to an open source repo today. The idea that adding yet another concept to the pile will make things better is something I can't agree with.

Will it enable more capabilities? Yes. Adding features generally does that.

Aside from the "it's already complex enough" argument, there's also the fact that 90% of changes I've seen in my daily use of git don't require this feature. This means the feature will be misunderstood, misused and often not used when actually needed.