I would caution against his opinion. There is a lot of speculation that he is paid to do coin promotions on his twitter account.
When he promoted Verge, its price doubled overnight. Rumor is that he met with Verge people the night before, and was paid to do this post the next day.
Of course, do you own research to come to your own conclusions, but the heavy amount of speculation begs consideration.
Some articles to read:
https://news.bitcoin.com/cryptocurrency-influencers-accused-aiding-pump-dumps/
https://www.financemagnates.com/cryptocurrency/news/john-mcafee-pumping-cryptocurrencies-cash/
https://www.financemagnates.com/cryptocurrency/news/john-mcafee-pumping-cryptocurrencies-cash/