In the case of M&A, how does a transfer of VMware licenses and support from one MyVMware account to another officially take place?

In order to transfer VMware licenses and support, a License Assignment and Transfer Form (LATF) must be filled in. The desired licenses as well as information about both parties involved in the transfer are to be filled in. The form is available within the MyVMware portal or is provided by VMware Support upon request.

Sources:

License Assignment and Transfer Policy_VMware_as is 2016-08-08

Official VMware Knowledge Base Platform (https://kb.vmware.com/s/article/2016482?lang=en_US&queryTerm=License+transfer) retrieved 2016-08-05