Did you verify whether it's the real McAfee Twitter account that is promoting this group?
Use something like the metacert browser plugin
https://next.metacert.com/ in order to check this. If it's not the real Twitter account, then it's almost certainly a scam. Please double and triple-check your sources, guys

I checked, it's real. One thing to note though, is that McAfee has come out as a paid shill:
https://www.theverge.com/2018/4/2/17189880/john-mcafee-bitcoin-cryptocurrency-twitter-icoI don't think it's an April Fool's joke either.
The Telegram channel says it'll ban shilling, but I still wouldn't trust any recommendations in it. Make sure you don't get victimized.
All these so called experts are just selling themselves for money...