They have workarounds. If you prevent multi-tenant from sharing their threads on the same core, that eliminates the most desirable goal of an attacker. However

They have workarounds. If you prevent multi-tenant from sharing their threads on the same core, that eliminates the most desirable goal of an attacker. However it does not eliminate the vulnerability within a single tenants own threads. You also have to think about all the web shops that are out there that are just running proxmox or a cloud reseller who reintroduces the vulnerability in their multicore VPS setup