On: “I'm wiping this repository away”

[hackaflocka]

"What's" is a common English word. "API" is a common term in English.

Combining them together should not be a copyright infringement of "WhatsApp."

[pbhjpbhj → hackaflocka]

You mean trademark infringement.

"Whats" isn't a generic term in the computing field. "WhatsAPI" isn't a dictionary word, it's a colocation of Whats and API, the first element being chosen specifically to render association with WhatsApp. The use of WhatsAPI differs in only one letter from the trademark.

IMO provided they headline the fact they're not associated nor extraordinarily authorised by WhatsApp then there would be no actual trademark issue; the law I suspect will see it quite differently.

[MCRed → hackaflocka]

The Trademark examiners are actually generally pretty good at this sort of stuff. You can search trademarks at USPTO.gov

I've seen numerous application turned down for using generic terms like this.

Probably the one and only time I'll say the government does a good job.