Is the comma after ‘theatre’ optional?

It's wrong, rather than optional.

Thanks, hingehead.

Why is it wrong?

As hingehead seems to be not around, could some other member please help? Many thanks!

I think that the comma gives the sentence a sense of drama by setting apart the proceeding possible scenarios.

Because commas separate clauses (among other things).

Dead or alive is integral to the statement - not a separate clause or modifier.

Consider how ridiculous the sentence sounds without it:

"no one knows whether he or she will come out of the operating theatre"

Clearly wrong - everyone comes out - the whole point of the sentence is 'dead or alive' - separating it from the main clause is just awks IMHO.

Infrablue's comment has some merit, commas can be used to indicate pauses in direct speech, but the sentence isn't puncutated as direct speech. Try saying the sentence out loud with a pause before dead or alive. Feels wrong to me.

My other concern is the use of two commas in the sentence indicates that the bit between the two commas is 'non-essential' added information when it clearly is.

I'm not explaining that well, so here are some examples:

Gunpowder is not, of course, a chemical compound.

His latest film, Calypso Dreams, opens next month.

Take out the middle and the sentence still conveys meaning whereas if we do it with your sentence, we get

Status counts for nothing dead or alive.

Warning: I am a native English speaker with no formal qualifications in English language and grammar (apart from my Grad Dip in Professional Writing). That's not a boast, I'm seriously saying this is my opinion and I'm often wrong.