WhatsApp recently released a list of Phones and OS that it will stop supporting by the end of this year, meaning any phones running these versions will stop receiving updates.
According to the release, all phones with Nokia S40 will stop will stop
Similar, Any phone with Android 2.3.7 (Gingerbread) will also stop receiving updates but from 2020. iOS 7 and older will also be unsupported from Feb 2020.
