WhatsApp rolls out the new update via Google play store by bringing the version to 2.19.332. The new WhatsApp update redesigned the Facebook footer on WhatsApp welcome page, settings page and on a splash screen. Similarly, the Facebook footer works on both Light & Dark mode while the dark mode can be enabled on WhatsApp by enabling the dark mode in system default settings. The Facebook footer designed on White color in the dark mode view. 
Redesigned Facebook Footer on Settings Page
Similarly, on the Splash screen on both dark and light mode. 
The dark mode on WhatsApp can be possible by enabling the dark mode on the system default settings.