Product : Microsoft, HyperV/2019, DataCenter
Feature : Max Consolidation Ratio, Host Config , Hypervisor
Content Owner:  Roman Macek
Summary
1024 vims/host, 2048 vCPUs/host
Details
(no major updates with WS 2019)
Server 2012 supports a maximum of 1024 powered-on vims per host and a maximum of 2048 virtual CPUs per host (in case of running virtual machines with multiple vCPUs the limit that is reached first applies).
Actually achievable maximum number depends obviously on workload characteristics and hardware configuration.