His proposal for the USA national reserve of Bitcoin is nothing interesting. The USA will not use their money to purchase bitcoin, and they only want to hold bitcoins seized from "criminal activities" in the past. There would be more interesting news if they announce that they will assign their national fiat currency or gold to buy more bitcoin - that actually has not yet happened and not in their plan at the moment at all
Basically, even though Trump is the president of the United States, he doesn't have enough power to do that even if he wants to use the budget or sell gold to buy bitcoin. That power belongs to the National Assembly, no agency or individual has the authority to make decisions on its own.
From Trump to Melania tokens and more activities, the Trump family actually are using their names and influence of Trump as a current President to at as much money as possible within his four years of a second Presidency term.
I see it as an abuse of power and that may be his main purpose in changing his attitude towards crypto compared to his previous term. He doesn't take bitcoin seriously or intend to make the US a crypto hub, instead he just says nice things about crypto to help his family make more money.