I know that senior admins have the right to change maps at their leisure as long as it is not "rapid"(not defined well enough) but I still do not think that admins should not have this power and here is why.
One persons map preference does not reflect the entire servers map preference and the whole point of an admin is to make the servers experiences better not worse.
I think that the admins should at least call a vote to see whether the server wants to change the map before he/she changes the map unless the map is crashing the server.
Here is a poll to see what people think.