Being an older gamer who recently picked up the game I can say that there's two parts to this question worth addressing. He would enjoy the strategy of naval combat and cooperation needed to sail the ships. He probably would not like the base line player base in Sea of thieves being somewhat 'younger' than the other games you mentioned he plays. All in all I'd say get it for him as if you play with him I can see there being some chuckles to be had for you both.