This is actually already available in recent Windows Insider Preview builds, so developers can start testing their PWAs right away. (neowin.net)
But if you're still looking to stick with Windows 10 Mobile for the time being, it's not a bad deal for one of the most recent Windows phone releases. (windowscentral.com)
«The most recent Windows Phone update from Microsoft is indicating the Samsung Focus v1.4 update may happen sooner than later.» (windowsphonethoughts.com)