News G.Skill intros 96GB DDR5-6800 CL32 and 32GB DDR5-6400 CL28 memory kits for Intel-based machines

When will we see 64 GB UDIMMs? Some motherboards got support for them over a year ago.
Micron and SK Hynix still only list 16Gb and 24Gb memory IC. Samsung does list 32Gb but it's in a non-standard configuration and only sampling as opposed to mass production. Given that it's been over a year since Samsung announced 32Gb IC and there's still nothing in mass production it's a safe bet not soon.

I'd love to know what the holdup is since not only does it enable 64GB UDIMMs but single rank 32GB as well.