There have been tips that TSMC has pulled its production schedule forward, but the foundry basically reiterated that risk tapeouts of 3nm chipsets will commence later this year, while mass production won't happen before the second half of 2022.
We expect it [3nm] to be a big and long-lasting node," claimed TSMC during the Q&A session, and the timespan between the low-yield risk production and the actual chip shipping to phone makers is up to a year, so Apple's iPhone 14 in fall '22 checks out as the rumored big 3nm customer."
This is the same schedule that TSMC has been advocating for a good while now, even though it announced a $100 billion capital expenditure spree into development and production of new chip production process nodes in the next few years.
Thus, the first phones with processors built on the next-gen 3nm node could very well be the iPhone 14 series, just like the iPhone 12 was the first to offer a 5nm chipset. The iPhone 13, on the other hand, will flaunt an improved second-gen 5nm A15 processor. Apple's focus with it will most likely be on improved efficiency rather than increased performance, given the high 120Hz refresh rate display rumors for its upcoming iPhone 2021 series.
As for the iPhone 14, the 3nm node will bring smaller footprint with slight 11% performance increase, and greatly increased power efficiency (-27%), as you can see from TSMC's slide above, which would most likely further cement Apple as the architect of the most powerful mobile chipsets around.
Those numbers also show that the performance boosts from moving to new production nodes are becoming increasingly smaller, so the 5nm and 3nm nodes will be with us for the foreseeable future, as mobile processors are already powerful enough for most any task you can throw at them.