They have long been an Intel allies since the days of Pentium Inside. Intel were paying billions to Dell to not have any AMD's product in their lineup. Dell even said the missing AMD were because there were no customer demands. Only after the AMD vs Intel case ruling, Dell decided to have one or two AMD machines just to make things look "better". My guess is in reality Intel runs deep inside their blood.

This may be attributable less to a lack of enthusiasm and more to the physical size and TDP of Epyc CPUs. Additionally, it would be very hard to take advantage of Epyc's increased PCIe lane count at half-U densities (which is, of course, not relevant to all use cases) and would likely constrain number of memory slots.

Personally, I've never been convinced that such high server densities [1] provide a net benefit. Ever since "blade" systems first came out, and through the current availability of the half-U models (e.g. 4 per 2U) or even 2S 1U models, they've been plagued with thermal design issues and, sometimes, reliability issues due to non-commodity parts and/or needing to spin tiny-diameter cooling fans so much faster.

Until relatively recently, there wasn't even datacenter space available that could accomodate such systems at full density running at full load. What did become available was at a premium (in addition to paying a premium for the higher-density hardware in the first place).

[1] more than 1S/U or so