Technically, but GP is allocating over 95% of post-tax revenue to everything other than engineer salaries, which is probably extremely generous.
WhatsApp had 200M users in February 2013[1], which was a year before they were acquired by Facebook. Perhaps they wouldn't have gotten to 1B users without Facebook, but I'm sure they still would've grown in the last ~8 years, and fewer users likely results in lower costs. My guess is they would still be doing very well.
Even before the sale, most of the customers are non paying. They are offering the service for free in countries with largest userbase(India and Brazil I think). I really doubt it had reached 50 million paying at any point in time.
