[Affected versions]:

• Firefox 67.0.1, Build ID from Treeherder: 20190523020236

[Affected Platforms]:

• Mac 10.14.2
• Windows 10 x64
• Ubuntu 16.04 x64

[Prerequisites]:

• A new profile is created using one of the following locales: en-US, en-GB, en-CA, de, de-DE, fr, fr-FR.
• The "trailhead.firstrun.branches" pref was set to "join-privacy".

[Steps to reproduce]:

1. Open the browser and navigate to the "about:welcome" page.
2. Hover the "Enter email" field.
3. Observe what happens next.

[Expected result]:

• A tooltip with the "Please fill out this field." string is displayed.

[Actual result]:

• There is no tooltip displayed.

[Regression Window]:

• This issue is not reproducible on Nightly 69.0a1 (Build ID: 20190510214931). Considering this, using mozregression tool I have found the issue that introduced this regression. Here is the pushlog.
• From the provided pushlog it seems that Bug 1551751 broke this in Nightly.https://tinyurl.com/y3vymuoq

[Notes]:

• This issue is also reproducible on the other branches that display the first run modal.
• Attached is the recording with the issue.

Ed, can you please take a look at this issue?

This was an intended change as part of bug 1551677 as the accessibility and hover message made it seem like the email field must have a value when that's not true.