Rails 5.2.0 - scaffold `form_with` includes `local: true` by default - forms

Question

When I scaffold a Rails 5.2.0 app, my scaffolded forms are always generated with the local: true option included in form_with.
rails g scaffold Article title:string
Generated scaffold form
<%= form_with(model: article, local: true) do |form| %>
<% if article.errors.any? %>
<div id="error_explanation">
<h2><%= pluralize(article.errors.count, "error") %> prohibited this article from being saved:</h2>
<ul>
<% article.errors.full_messages.each do |message| %>
<li><%= message %></li>
<% end %>
</ul>
</div>
<% end %>
Generated HTML
<form action="/articles/1" accept-charset="UTF-8" method="post">
Note the lack of data-remote attribute
Documentation
I thought the default for form_with in Rails 5.1.2+ was to use remote AJAX / xhr requests with data-remote attributes? In other words, NOT include the local: true option.
See: http://api.rubyonrails.org/classes/ActionView/Helpers/FormHelper.html#method-i-form_with
By default form_with attaches the data-remote attribute submitting the form via an XMLHTTPRequest in the background if an Unobtrusive JavaScript driver, like rails-ujs, is used. See the :local option for more.
Note - rails-ujsgem was moved into Rails itself in 5.2.0 - https://github.com/rails/rails-ujs. So it looks like I should not need to add anything to the gemfile to enable the default form_with behavior.
Troubleshooting
I do use a .railsrc and a rails template file to customize my rails new scaffolds. However, I have tried disabling & removing both files and still get same results from new scaffolded apps.

Answer 1

To give a more complete answer based on my comment, here's how to add a template to customize the form partial generated by Rails when using the scaffold generator. I'm assuming here that you're using ERB, but the procedure is similar if you're using something like slim-rails to customize your view generators.
Create a file in your Rails project: lib/templates/erb/scaffold/_form.html.erb.tt
For this new file's content, a good place to start from is the content in the existing template. You can use gem which rails to locate the file that defines Rails in your current environment (with a result like /home/<user>/.rvm/gems/ruby-2.5.0#<gemset>/gems/railties-5.2.0/lib/rails.rb), and from there you can find the form template in railties-5.2.0/lib/rails/generators/erb/scaffold/templates/_form.html.erb.tt. Copy the contents of that file into your new generator template.
Try making some changes to the new template file, and then run the rails scaffold generator (rails g scaffold foo ...). You should see your changes reflected in the _form.html.erb file created by the generator.
Bear in mind that this template is 'doubly nested' ERB, meaning that it is processed with ERB a first time to produce a view partial, and then processed again every time your Rails app serves a request with it. That said, it's usually not too mind-melting to make a simple change, such as removing local: true from your new template
In depth info on customizing Rails generators is available at RailsGuides.

Answer 2

Think I found answer - and it's simple :) - the Rails scaffold templates for 5.2.0 explicitly include the local: true option.
5.2.0 Template for forms
<%%= form_with(model: <%= model_resource_name %>, local: true) do |form| %>
So I guess they wanted local: true as the default template for scaffolds. Probably for simplicity?
To find the scaffold generator templates
Thanks to this post for helping find the source: Override Rails scaffold generator
Find where your gems live with gem enviornment command
I use rbenv, so mine are at ~/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems
cd into that file and look for railties-5.2.0
search in rails/generators/scaffold/templates, or just search for local: true
here's the path: ~/.rbenv/versions/2.5.1/lib/ruby/gems/2.5.0/gems/railties-5.2.0/lib/rails/generators/erb/scaffold/templates/_form.html.erb.tt