Jetpack comments no longer show "Like" information upon hover, for Atomic sites

### Quick summary
The "Likes" on comments (not on the post, but specifically on the comments) show a Like count, but when you hover over that count, it does not show _who_ left those likes on the comment. This issue is specific to AT sites.

### Steps to reproduce
Create a WordPress site on a Business plan or higher.
Ensure [hosting features are activated](https://wordpress.com/support/activate-your-business-plan/).
Enable the Jetpack comments module via /wp-admin/admin.php?page=jetpack_modules.
Open any post and submit a comment.
Like the comment.
You should be able to hover over the Like count to see who liked the comment, like this example from a simple site:


### What actually happened
Nothing pops up when you hover over the Like count, and the Like count links to https://widgets.wp.com/likes/#


### Impact
All Atomic sites

### Available workarounds?
Not completely: notifications will show who liked your own comments, but not who liked other people's comments on your posts.

### Platform (Simple and/or Atomic)
Atomic

### Logs or notes
The issue is not reproducible on simple WordPress.com sites.

No source file or test is named. Reproduce the missing hover information on an Atomic site, compare it with a simple site, and trace the comment Like count that links to widgets.wp.com/likes/#. Done means hovering over an Atomic comment's Like count shows who liked it, without regressing the simple-site behavior.

Written by the indexing model from the issue text.