Is it possible for him to become that rich in such a short time
Yes nothing is impossible with bitcoin when it comes to financial investment, El-Savador whole story about debt might have been cleared right before that eight years you thought, one thing with bitcoin as an investment is that it secures the future for you, there's no how you could make an investment in bitcoin over a long duration and never have a reason to smile at the end, it appreciate, its a digital good store of value, its an investment asset, its secured, its anonymous, if you look at the the history from how it all started from 2009 till date then you could get more conviction that El-Savador or you could achieve a big dream with bitcoin adoption and investment.