Yeah, I especially liked the P4800X series. They were great as primary storage for virtual hosts. They allowed for higher density of virtual guests as Optane's storage performance still made the guests feel snappy enough. They also made database servers more performant as well. I'll be sorry to see them go, that's for sure.
Intel's response hints that Optane memory could move to a cxl memory controller. The leaked slides of Emerald Rapids show a CXL.mem as a feature, so perhaps they'll get the Optane DIMMs off the ddr5 memory controller and into some packages that remove the DIMM power/thermal constraints.