I would like to see, which of my servers actually support my client, so it would be nice to see the latest version they broadcast.
Also, it would be great to see the actual server version (e.g. 1.8), even if they claim to support later versions (using ViaVersion etc.).

I suggest showing the last compatible version below the player count in the server list, and actual version as a tooltip when hovering it.
For example, the tooltip could say A 1.8.9 server with compatibility up to 1.16.3.