Whether Mueller disappears now as he should depends entirely on how his “work” is defined. If his work is to explicate Russian “interference” in the election he has done so and has said in the indictment that it had no impact on the election.
If, as I suspect, his work to help coverup Obama/Clinton collusion with the Russians and other illegal activity (e.g., illegal warrant(s), wiretapping and “unmasking”) then he’s got to stay in business to preempt Congressional investigation. Obama/Clinton and the Democrat establishment are probably hoping they’ll win back the House in the midterms and can safely shut down Mueller then.
He is not going to disappear. Rather his new red robes will be delivered soon and you may then address him as “Cardinal Mueller”.