Earlier there have been reports that Microsoft is planning to bring Double Tap to wake to Windows 10 Mobile, devices that support the feature.
Now we have an Official confirmation from Microsoft Engineer Goran P through the Feedback Hub app which is available to all.
Microsoft Engineer Stated:
“Thank you for your feedback! We are aware of this issue. We are working on adding the support for double tap to wake for devices that support this feature.”
Double touch to wake feature is one of the most requested feature by Windows Insiders.