CZ was only expressing his opinion regarding the adoption by el Salvador is jus the beginning for another adoption that may happen in the future. CZ was talking about the possibility of the adoption that happened with el Salvador can trigger more countries to consider to legalize bitcoin as a legal tender on their countries to follow what already done by el Salvador.
I personally has the same opinion as CZ if we are entering the adoption to the crypto by countries and government. If the adoption that already done by Salvador will be a successful adoption and this will attract more governments to think to add bitcoin as a part of their legal tender. The adoption for crypto is just starting now.
Your question was also a bit confusing consider if the beginning means if it's just started and it will need more time for another country to come to adopt bitcoin in the future. I guess you're missing something from cz's post, right?