If anything I'd go so far as to say that unipolarity is already over and it's been over for years. There is a coup government in Perú right now, with american boots on the ground. Chinese investment and soft power continues more or less unabated, and the only thing staying on the path of BRI's projects is that the peruvians want to lengthen the route of the transoceanic railway. SOUTHCOM complains about chinese ports, but the fact of the matter is that the US has no use for peruvian minerals or brazilian soybeans and the pull of chinese money is too strong even for a comprador elite. The clown president in Buenos Aires wishes he could throw his lot in with the Americans, but the trade realities mean that he can't and neither could the junta joke that ruled Brazil not long ago.

South America might be a particularly edge case example in my view, but the most normative one should be the existence of countries like India and Turkey. Not massively powerful or isolated, not defined by anti-americanism, and still playing at their own game, talking to everyone at once according to their own interest.

The 'Suez Canal moment' is often taken as the siren song of european hegemony, not because it is the perfect chronological moment where european imperial power ceased to exist, but because all of a sudden something that was beyond the pale was not only possible but felt only natural. It is nonetheless true that, at the same time, the european empires were both collapsing before losing the Suez and still exist to this day formally (for the french empire) and informally (for all the other empires). The greatest material change is that those neo-colonial empires were subsumed into the American one.

So TL;DR just as european multi-polarity gave way to Soviet-American bipolarity without entirely dismantling european structures of power, American unipolarity has already given way to defacto global multipolarity. Too many countries simply don't take marching orders from Washington. There are far too many opportunities to raise capital aside from just New York and London. High tech weapons systems have been commoditized to the point where many can be produced, in house, by the Yemenis. And there are too many countries at the periphery of the American Empire who cannot but engage in political and commercial relations with the Empire's enemies.

It is not healthy to try and see the future, however it is not for nothing that the former british prime minister feels that Ukraine is a new Suez Moment. Things changing and are changing very fast. New settlements need to be reached.