`entity_embed.dialog` route should not use `_theme: ajax_base_page`; no longer required as of Drupal 8.2

The editor (ckeditor) is correctly displaying the fields selected for a custom view mode but does not choose to use an available custom template for that view mode. Here are the steps to repeat the issue:
1) Install default D8
2) Create new view mode short.
3) Add short view mode to Article.
4) Manage display of short to only enable the body field as trimmed.
5) install entity_embed
6) Text Formats and Editors (Config) drag the Embed Node icon to the active toolbar for Full HTML and check 'Display embedded entities'.
7) Create 'Article 1' with a good amount of text in the body.
8) Create 'Article 2' with an embeded version of Article 1 as view mode short. This works.
9) install bootstrap theme
10) Add a custom template to bootstrap: node--article--short.html.twig
{%
set classes = [
node.bundle|clean_class,
node.isPromoted() ? 'is-promoted',
node.isSticky() ? 'is-sticky',
not node.isPublished() ? 'is-unpublished',
view_mode ? view_mode|clean_class,
'clearfix',
]
%}

This is short:

11) Add a view which lists articles as ‘short’
12) For the view, when inspecting the html it correctly uses the custom template:

13) For Article 2 the rendered content is correct but when editing Article 2, ckeditor is not picking up the available template:

The editor should be displaying the embeded article using the custom template and it isn't.