CC Wei said N3E might be pushed forward one or two months.
The only comments I could find attributed directly to him were in April, "And pull-in, yes, we are considering that. So far, I still did not have a very solid data to share with you that how many months we can pull in. But yes, it is in our plan."
The March report from Morgan Stanley was that it could be pulled forward by a quarter to begin mass production in Q2 2023. That was back when N3 was still supposed to start mass production in September. We now know N3 mass production happened three months later than that, but the open question is: was that due to issues that will also delay N3E or due to issues specific to N3? We don't know that answer. If N3's delay from September to December was due to issues that were addressed by N3E, those three months will not push back N3E's debut but instead compress the timeline between N3 and N3E even further.
Also consider the yield graph that was leaked back in August, showing 80% yields already for N3E on "mobile and HPC test chips". I don't know what yield TSMC requires before considering a process risk production or mass production worthy, but N5 entered risk production with yields below 80%. TSMC has always introduced new nodes that improved upon previous nodes in density, power or performance - often all three. So it makes sense you'd need and want a lengthy risk production cycle to insure that those improvements can be delivered consistently in volume, with good yields.
This is the first time they've introduced a new node that has worse density, worse power, and worse performance. Maybe I'm crazy but it seems to me that risk production ought to be a lot quicker when you are rolling out a node that's less aggressive than what came before, instead of like in every other case more aggressive. Additionally, I would think that customers would be more likely to consider buying some risk production wafers to use in their products if they get a bit of a discount to reflect the slightly reduced yields.