nextmap votes should ultimately be finalized at intermission (with the ability to add candidates, and vote, and change your vote via a vote menu up to the final chance to vote at the intermission). So in the case of such a nextmap vote. So once such a feature is implemented, the adding of nextmap candidates during a match would not require as much notice as the current nextmap votes.
Regarding mute votes, even once /suggest ignore is implemented, there would still be certain need for mute votes (such as ghosting, excessive flooding of the chat, etc), which can have major negative impacts on the match, but also wrongful mutes can have a negative impact on the match, in terms of team communication, not to mention potentially resulting in a negative atmosphere. So it would be important to get notification of such a vote.
A wrongful kick vote of any kind can have a negative impact on the player being kicked, as well as on the whole match if that player was contributing in a positive way towards that match. Thus why such a vote should be noticeable.
Examples of other kinds of votes that require sufficient notice:
- Map restarts
- Draw votes
- Change map votes (perhaps should be removed, as draw votes combined with next map has the same overal functionality)
- Admit defeat votes
- Force spec votes
- Deny build votes
- Unmute & Un-deny build votes
Something else that all those votes have in common is that in the current implementation, from the time of notice, to the time of completion, the voting is open for a maximum of 30 seconds, which in itself creates an urgency (As if you are not given sufficient notice, it can be easy to completely miss such votes).
I would say that the only current kind of vote that doesn't require "extra ensured notice" are poll votes (which might be better done in a vote menu that could be open through the duration of the match).
Couldn't a vote sound be done in such a way where when occuring, players would definitely notice it and tell that a vote has been occurred, while not being distracting from the gameplay (nor spectation)? Such a balance is what would be ideal. Consider how the chat sounds are done. You can tell that someone has submitted a chat specifically as general chat as well as specifically as team chat, when such chats occur, yet those sounds don't distract from the gameplay (nor spectation).