‘To keep up with the latest advances in tech, we routinely stop supporting older operating systems to point our resources to supporting the latest ones,’
While these phone brands have not been phased out and are still very much in the market, the Whatsapp upgrade will, however, affect them as their operating systems will not be compatible with WhatsApp’s new features.
This simply means that after the stated date, users who own the affected phones will stop receiving WhatsApp security updates and new features.