> uses an _embedded_ silicon interposer
It sounds like they're using TSMC's new LSI (Local Si Interconnect) technology, which is their version of Intel's EMIB. It's essentially small islands of silicon, just around the inter-chip connections, embedded within the organic substrate. This gives the advantages of silicon interconnect, without the cost and size restrictions of a silicon interposer. It would not be visible from just looking at the package.
https://www.anandtech.com/show/16031/tsmcs-version-of-emib-l...
https://semianalysis.com/2022/01/06/advanced-packaging-part-...
The comment was that the press had reported that the interposer wasn't available. This obviously uses some form of interposer, so the question is if the press missed it, or Apple has something new.