Yes, if you're the server admin and you "kick [botname]" a bot... they go away for the whole game until you "sb_add [botname]".
Some friends of mine and I like to sometimes do solo runs so I'll slay them in the safe room so they can watch and I'll start up HLDJ with a good prorun tune and have at it...
Then it's the next person's turn and 3 slays a good song and have at it...
It's loads of fun.
I tried kicking the bots and it said something like "This player cannot be targeted".