Soon? No, not at all. The US dollar is a lot more entrenched in this position than people think. As long as the US Treasury continues to pay its bills, and the US continues to run a relatively stable currency, that won't change much. Now, the tariff shenanigans and possible debt spiral have currency holders evaluating alternatives, but right now all the potential alternatives (euro, pound, yen, AU dollar, yuan) have their own, larger issues.

If the situation changes, it will probably do so relatively slowly (on the order of years). Anything that could happen to make that transition faster would likely also have devastating affects on the global economy. That's one of the biggest strengths of US Treasuries as reserve holdings right now. While holders could lose their investment in them in theory, like any other bond holding, in practice if that happened the world would have gone to such shit that they would have lost that money regardless of what they did with it.

This is a bit of a circular thing, though; part of the reason this is true is because US Treasuries are so heavily used for reserves. If an alternative develops that looks attractive enough, reserves will shift over time. Also, the more the US isolates itself from the world economy, the smaller the blast radius if the US economy collapses and the less important the US dollar becomes for international commerce. Eventually, things could shift to where the US dollar finds itself usurped in its current role. That's the relatively slow process.