I think that's a very poor reading of the article, backed up by a poor understanding of what has already been delivered, and is in the process of being delivered, but has not been used yet.
Absolutely no one does not believe there's a time limit - there's conflicting views on what that time limit is, and what the drivers are, but the Autumn of 2024 seems (to me) to be the solid one.
There is no one - no one - who does not believe that Ukraine will have a much better Summer and Autumn than Russia. There's no one who believes that Russia has a force in waiting with which it can undertake a large scale summer offensive/counter offensive - Ukraine OTOH does have that force, and it gets stronger and better equipped each week - the Challenger and Leopard tanks that have been delivered haven't been used, the number of Leopard tanks will probably hit 150+ by late autumn. The US Abram's tanks won't be ready until next year. It's also interesting that Ukraine has not used the force it's been building in its offensive around Bakhmut, while Russia has expended one of its more capable forces in attempting to defend it.
One can argue that the promises may have peaked, but given that deliveries are anything upto 6 months or a year behind promises, that's not a problem that Ukraine is effected by this year.
The question of fast jets is not one solely governed by the US - F-16 is the prefered candidate, not because of it's particular qualities, but simply because there are lots of them, and it would be easy to put together a multi national package that didn't effect any one state disproportionately. However, if Europe - which has far more skin in this game than the US - decided that the US 'no' really does mean 'no', unlike all the other times they've said 'no' - then there are other options that would not require US permission.
It also fails to take into account that US policy is impacted - not set, but not indifferent to - it's standing in NATO. If the US refuses to allow other states to donate F-16's, it's standing is reduced, people become less likely to support its policies other areas, or indeed to buy it's equipment - but if other states were to provide other aircraft (Typhoon, Mirage 2000, Gripen etc..) in the face of US opposition, the US would suffer a huge lose of face, and it knows it.
Understanding how NATO works on a political level is informed by an understanding of Early Mediaeval kingship - Kings stay kings by protecting and rewarding the leaders of their warbands. Biden understands that, and unlike Trump, he cares a great deal about US standing and leadership in NATO. 'No' is unlikely to be the last word in this...