NSL Gathers can be played on ns2_metro until the next patch release. You can vote for the map in the gather list as any other map but you will have to play in the same conditions as the players of the last showmatch.
Be aware that the server "NA Metro Showmatch" does not run NSL Mod and CompMod and is really often updated. To join this server, you will need to switch to the beta branch of the game on Steam (right click on your game in your library, "properties", "betas").
If you have any feedback about the map, feel free to share them on UWE NS2 discord but take note that the map isn't likely to change much as it's due for next week.
Join here: https://gathers.ensl.org/
Today, at 12 PDT - 15 EDT - 21 CEST, join us to watch some epic 6 v. 6 games on the upcoming official map before its release (hopefully next week): Metro!
It will be streamed on both: