It’s known as the AWD (an ‘Amazonese’ acronym for “Amazon Warehousing and Distribution”) Program, aka “Amazon Upstream Storage” (aka “Downstream” in certain circles), and you’re right - Amazon has dispatched more than a few email missives regarding it.
One can begin learning more about this topic from the ‘Overview’ section of the Amazon Warehousing and Distribution (link, Seller Central) Dashboard, and from the SHC’s (“Seller Help Content” in ‘Dogtamerese’) ‘parent page’ for the subject, Amazon Warehousing and Distribution (AWD) [link, SHC], as well as from the Help Hub articles which are nested beneath that ‘parent’ in the left-hand ‘tree’ which replaced the old SHC Index/Table of Contents.
As @ASV_Vites, @VTR, and others discovered when Amazon really began hyping the program in the late summer of 2022, there are some stringent restrictions - some nonsensical, some not - as to what goods are eligible; most of the chatter that I’ve seen, in both the OSFE & the NSFE alike, seems to be about that, or about the monkey wrench thrown into various workflows that Amazon’s use of “IUSL Virtual Warehouse” - and scanty documentation concerning that - produced.
The available evidence seems to suggest that the kinks are being slowly worked out of the program, and I think it’s probable that the Mesa, AZ facility is likely destined to be a part of that - certainly, members of the AGL (“Amazon Global Logistics”) Program seem to be filling up the pipeline rapidly - but I would not lightly dismiss the cautionary tale to be found in the 31Dec2022-begun thread AWD Experience (Dec 31 2022) Full Container FCL Amazon Warehouse & Distribution Experience (link, NSFE) over in the wannabe forum NSFE.