Earlier this year, WhatsApp confirmed in its plan that it would drop and end support for older versions of Android and Windows OS from 8.0 and older devices, starting from December 31st, 2017.
Meanwhile, the company also announced its deadline for other platforms. For example, the Nokia Series 40 devices will be supported till December 31st of 2018, while Android 2.3.7 and below or older versions will be supported till February 1 2020.
So, starting next year you will not be able to use WhatsApp on these platforms. At least, this will expand the features of WhatsApp and will of course, make everyone upgrade to newer version to enjoy more exclusive features of WhatsApp.
If you still use BlackBerry device or Windows phone, you can look for Top 8 Android Smartphones With Gigantic And Massive Storage Space and upgrade.