This article is extremely confused (probably because the original TSMC Press Release is a major fsckup clearly written by someone without a clue).
(a) There are two TSMC N3 processes, the first one (originally just called N3, now called N3B) and a modified one called N3E.
(b) Apple's first N3 products will be on N3B.
(c) N3B gives, among other improvements, a density boost of 1.7x and a power reduction of ~25%
N3E gives, among other improvements, a density boost of 1.6x but a power reduction of ~34%
(d) It APPEARS to be the case that N3B began volume production in late September:
TSMC’s 3nm era set to begin in the coming weeks
www.tomshardware.com
(e) It APPEARS that this ceremony refers to N3E, but it's honestly impossible to tell whether N3B was delayed three months, or N3E is being rushed into production ASAP. My GUESS is that it's the latter, N3B was on schedule in September, but N3B is yesterday's news, an experiment that pushed things too far and that is being abandoned by TSMC as soon as contractual obligations to Apple (and anyone else?) are done.Since N3E will be the only option going forward, that's the one they want to get all the media oxygen.
(If this theory is correct, it's something of a change for TSMC. In the past supposedly "unsuccessful" experiments, like 10nm, were not just useful learning exercise, but stuck around for a while for others customers to use if they wanted. N3B looks like TSMC have no interest in keeping it around longer than necessary.
My guess [once again a guess] is that the TSMC engine broke down because of covid. Problems with N3B that, in the past, could have been figured out via engineers shutting between Taiwan, the Netherlands, and Japan, had to be handled more slowly and inefficiently via Zoom calls and eventually TSMC made the call to just abandon the most aggressive aspect of the design [the EUV double-patterning] and switch to a less dense, and less aggressive, set of design parameters.
Probably if Apple were not already somewhat committed to N3B [having already "delayed" an iPhone chip, in that the A16 is a disappointing A15 moved to N4 because N3B was not ready yet, and having already delayed the next set of high end Macs] TSMC would have dropped N3B without anyone even really knowing, and just shifted to N3E as "N3".)
