Documentation from Intel confirms the future Alder Lake-S architecture will switch to LGA1700. This has been rumored for some time now. The current Comet Lake-S and the upcoming Rocket Lake-S use LGA1200 but the generation after Rocket Lake-S will once again switch to a new socket.
Besides confirmation of LGA1700, VideoCardz reports Alder Lake-S will also be the first Intel desktop chip to support DDR5 memory. It's believed that Alder Lake-S will use an ARM big.LITTLE-like core configuration, with Golden Cove and Gracemont cores.
A fresh leak from @momomo_us revealed that Intel now also lists LGA1700 socket on official resource website. This is the first confirmation directly from Intel on the new socket in regard to Alder Lake-S. Previously this rumor was only mentioned by manufacturers specializing in testing equipment for Intel platforms or the leakers.