Workstation Pro versions before 17.5.2 aren't "free". They still were licensed product that required you to purchase a license. It's only 17.5.2 and later that do not require a license.
Let's all recognize that there are no longer "entitlements" in Broadcom's eyes for the desktop hypervisor products. In their eyes, "entitlements" are active subscriptions. All perpetual licenses (for all of their products) have been thrown out the window.
You get Site IDs when you have subscriptions. Desktop products have no subscriptions, therefore no site IDs.
What bothers me is that they don't honor those perpetual licenses for Fusion and Workstation they inherited from VMware. They really should make available Fusion and Workstation installers for people that purchased licenses instead of forcing those users to go to third-party sites. (They should also make the licenses that were purchased available as well, but I'd take the installers at a minimum). What harm would there be to make those old versions available? We all know Broadcom no longer supports or updates those old versions, so Broadcom would really have no other cost or liability other than to host the installers.