Changing the %%focuskw%% is not reflected in the snippet preview

[moorscode]

Replaces #11298

Please give us a description of what happened.

When creating a new post, using the %%focuskw%% replacevar is not being filled with the value entered in the Focus Keyphrase field.

When the post has been saved and reopened, this is being applied as expected.

But, changing the focus keyphrase does not update the snippet preview with the new value.

How can we reproduce this behavior?

1. Create a post
2. Enter a focus keyphrase
3. Use the %%focuskw%% or Focus keyphrase replacevar in the snippet preview (title or description)
4. See the replacevar not being updated to what is expected
5. Save the post
6. See the variable is being replaced with the current value
7. Modify the Focus Keyphrase input value
8. See the replacement is not being updated to the new value (and the highlight is being removed)

Technical info

• WordPress version: 4.9.8
• Yoast SEO version: 9.0-RC3

• If relevant, which editor is affected (or editors):

• Classic Editor
• Gutenberg
• Classic Editor plugin

• Which browser is affected (or browsers):

• IE11
• Edge
• Chrome
• Firefox
• Safari

• Relevant plugins in case of a bug:

• Tested with theme:

[moorscode]

This is still relevant in 11.2