Have they? As far as I'm aware, sleep states are "supported" in hardware well enough, but doesn't prevent software/settings from not using them correctly.
Not that I blame them, there are many different sleep states from core/package level [0] that map onto system/platform level sleep states [1]. Fucking confusing, and I'm sure something is waking it up. Have you checked Windows Task Scheduler? My college laptop had a Norton Antivirus scan wakeup at 5am every day and would be re-enabled every Windows Update, similar pain to you
Source requested, I follow this news closely and have not seen anything that AMD is using Intel's fab.
Nvidia praised their test chip and that indicates they might use Intel's fab. They have not definitively announced that either (https://www.tomshardware.com/news/nvidia-ceo-intel-test-chip...)
Amazon was using Intel Foundry for packaging, not fabrication. And Qualcomm was considering 20A (https://www.pcgamer.com/intel-announces-first-foundry-custom...) in 2021, but there was a rumor earlier this year that Qualcomm might not use it after all (https://www.notebookcheck.net/Qualcomm-reportedly-ditches-In...)