Apostrophe is being encoded in page title

Tested this on a clean D8 RC1 install with the git checkout of 8.x-1.x as of about 30 minutes ago. So this already includes #2584835: Title tags are double-encoded

To repro:

• Clean D8 RC1 with only Metatags installed (no pathauto needed)
• Add a metatag field to article. Leave all the defaults blank.
• Create a new article.
• Set node title to Test metatag's apostrophe handling
• Set metatag Page Title to [node:title]
• Save node.

Node title will show as Test metatag's apostrophe handling

Next:

• Edit the node.
• Change title to Test metatag’s apostrophe handling . (The apostrophe is slightly different.)
• Save node.

Title now displays correctly.

I don't know where that other kind of apostrophe is coming from on the client site. It's not on my keyboard. Possibly it's being copied from a word processor? At any rate, the "fancy" apostrophe works but the regular one does not.

I assigned to myself because I'm still looking into it but if anyone happens to know what's going on feel free to jump in. :)