I think of it as similar to Skier Mikeala Shiffrin in 2014 as saying " I want to win 5 gold medals in the 2018 Olympics". Be bold, have lofty ambitions and tell people about it, so that you are going to have to work to be accountable for achieving those goals.
She only won 2 medals in 2018, but she wasn't afraid of people doubting her because she wanted to achieve greatness. I don't know the context of Devin White's statement, but I hope he just doesn't give a Fu@k about the doubters and is gonna grind the next 5 years and make his bank.