Even at Amazon, when I left work I left behind all ways to communicate and my bosses respected that. Nearly a decade there and never did a boss try to reach me on vacation.
Also been my experience doing technology in big banks for 20 years. Barring extraordinary circumstances, if you need to call someone who's on vacation that's an indicator of a broken process and unnecessary operational risk.
(I've also seen a person who believed he was indispensable and thought because of that he could behave like an asshole. Very satisfying to see him get fired.)
(I've also seen a person who believed he was indispensable and thought because of that he could behave like an asshole. Very satisfying to see him get fired.)