[1] https://www.theguardian.com/technology/2016/jan/18/whatsapp-...
It's possible that they were only enforcing it in some regions, though.
All pricing was entirely optional
Here's one reference to a different price (can't find lifetime except for people complaining that Facebook didn't honor it on original ToS)
But I remember other people started to en masse switch to other messengers like Viber(?). And Whatsapp had to stop enforcing the fee.