Hi Satman ,
Yes AMD Ryzen work with VMware ESXi 6.5 but only in home labs or in small environments . Because to when you installed ESXi 6.5 on AMZ Reyzen may be you will get PSOD on same time or latter . Although they have fix the issue like PSOD and many other Linux kernel issues , Disabling SMT is not good fix as it effect the performance.
Rajiv Pandey
vthesis.wordpress.com