Push notifications will be turned off for Windows Phone 7.5 and 8.0 as Windows says these devices have reached the end of their support dates.
Windows says services for these versions of Windows will be discontinued over time.
From February 20, Windows Phone 7.5 and 8.0 will also not be receiving additional live tile updating and the find my phone feature will be switched off.
Windows does note that notification services will continue to function for Windows Phone 8.1 at this time, and newer phones running Windows 10 Mobile are still fully supported.
These phones were released in 2011 and 2012, respectively.