

This does allow downgrade rights for previous versions of Office. The licensing terms require you to use the exact same license type on both machines (no mixing M365 with VL).

Additionally, they must be VL licenses, not retail, to get remote access rights. Perpetual License Office is licensed per machine except for remote access! You don't need a license for the server but you do need it for the devices accessing the server (in other words, the PC the user is using to RDP to the server). This includes RDS or any other remoting solution. Only certain tiers (Enterprise and Business Premium plans) include Shared Computer Activation, which is required in remote access scenarios. Subscription Office (Office/Microsoft 365) is licensed per user.

Also, OP specifically asked about running on a Server not running a web app. You are talking about running the web app? That doesn't apply to Office 2010, which OP asked about. Being one single user, if the application doesn't need to run as a service, the user can run Excel from his/her 365 portal. Yes, doing a server installation for only one user is not worthy, but feasible with Office 365 ProPlus.

I don't know what your reply means in this context. The question was about licensing Office on a server. The user connected to the server with RDP can run any Office apps like it was from any other computer, it doesn't need to install Office on his/her session, or install on the server. Any other version of Office not only is a license violation, the installer won't even install it. Running Office on an RDS Server requires a Volume License or Microsoft 365 Apps for Enterprise installed in Shared Computer Activation mode. To me it sounds the installation of the Office app on the server could be run by a licensed user. Each Microsoft 365 account can install software in at least three devices.
