To me smaller diffs – even 2-3 lines less in a 500+ lines change worth of PR – are an objective improvement.
Though I can agree that’s the much smaller hill that nobody should die on. We need semantic diffs much more. Not having that ruins reading the changes, almost always to a level when I need to just pull the branch and go read the code in my editor as opposed to reading in GitHub’s UI. 
Tell me about it… I only have so many hours in a day. I’ve tried setting up Mason, Telescope, and all the rest in NeoVim, but haven’t gotten the settings dialed in. And I already have coc-elixir set up, and chugs along like a champ. (It hasn’t had a commit in like 2 years).
It’s quite the first world problem… I think I’ll have to switch when the Expert LS is released. But who knows… Maybe it will just keep working somehow.
Just get AstroNvim, it has it all pre-configured. It took me 2-3 hours to figure how to configure that and I was not happy but it was much faster than doing everything with Neovim from scratch AFAICT.
You’re probably right… I tried AstroNvim once, but it collided with a bunch of my existing keymaps, and I gave up eventually. It did seem to be the best of the Nvim “distros” though.
Well I am not here to do free PR for it, just sharing that it worked (and still works) amazingly well for me. And you can configure keymaps further as far as I am aware (said so on their website) but full disclosure: never tried it.
I do prefer trailing commas for multi-line scenarios, but I don’t want it as an option: it should only be added if it’s the official standard. The lack of bikeshedding on styles is the best feature of any formatter.
While the reduced diff size is nice, I don’t really care about it much. What I do care a lot about is when I sort/move around items and forget to add a comma back in, and then the compiler spits out an error.
An alternative to adding the trailing commas would be making the formatter smart enough to add missing commas back in. That would solve my only real annoyance with the lack of trailing commas without needing any changes to the standard format.
As far as aesthetics, that style can only be subjectively loved or hated, and I don’t love it, lol.
Objectively, it seems like the worst of all options in that it doesn’t optimize diffs, nor does it allow easy reordering of items. I was pretty into Elm years ago and I remember Evan made a good case as to why that style, but I can’t remember what it was. 
It does make nicer diffs as it only changes one line when you add a new item (so long as it’s not to the start).
EDIT: actually never mind, it’s just the same problem in “reverse” with the caveat that it’s probably more common to append than to prepend. Not sure what I was thinking there.
I know this is a throwaway comment as it would have never happened due to the syntactic goal of being similar to Ruby, but since Elixir also borrows a lot from Clojure all of this bikeshedding could have been avoided with having no commas at all! 