Not with a living will it wouldn't. If the patient's wishes are in black and white, signed and witnessed...mind you, you have that weird healthcare system going on where poor people are left to die in the streets.
Ya damn weirdos.
Even with a DNR and executed living will, the hospitals have asked for next of kin consent in every end-of-life case I've been witness to - that's at least three in the last ten years.
They also require a separate DNR for "death in transit", meaning if they're transferring someone from hospital A to hospice or hospital B and they flatline in the ambulance, and there's not DIT DNR (the letters give me headaches!), they will attempt to resuscitate.
2 different hospitals, and one hospice.
Go back another five or so years, and there was a horrible mess with my great-grandmother, to the other extreme. Her care facility decided that "living will" meant no medications, even basic antibiotics.
They're a mess over here.
I'm fairly certain the only facility that honored the person's living will verbatim was the VA hospital with my uncle.