1. Server owners should be able to add tags if we want to make server owners keep the tags up to date, but it could be a problem if someone puts some inappropriate content there🤔
2. location tag would be useful

maybe decide on a default set of tags that server owners could choose from (location, main gamemode?, public/private) to avoid misuse.

if there is a "official" server browser that is able to use the tags to filter servers, then yes the tags would be really useful

1. Server owners should be able to add tags if we want to make server owners keep the tags up to date, but it could be a problem if someone puts some inappropriate content there🤔

Maybe my phrasing was a bit unclear, but what I meant by "add" was "create new".
Of course server owners are able to change the tags on their own servers whenever they want to, but it's unclear whether we should let them create new tags, like e.g. here on GitHub, or give them a set of official tags they can choose from.

maybe decide on a default set of tags that server owners could choose from (location, main gamemode?, public/private) to avoid misuse.

Yeah that would be the alternative.

if there is a "official" server browser that is able to use the tags to filter servers, then yes the tags would be really useful

That's the plan. The official cs2kz website will have a "servers" tab that shows all the globally approved servers and their public information (like IP and owner), and you can search there. The main purpose for tags would be searchability.