There's an old saying that goes ”the nearer the bone, the sweeter the meat”.
It's wrong.
Well, half wrong.
With wet heat cooking bone does add flavour and, because it contains lots of collagen, it adds texture too.
But, with dry heat cooking – like a Fore rib roast or a grilled T-bone – the bone contributes virtually nothing. It doesn't add to the flavour (except maybe the first millimetre of meat adjacent to the bone). And there's no difference in tenderness either. Or nutritional value.
With dry heat cooking, the only advantage of keeping the bone in, is there's a bit less surface area to lose moisture as it cooks. But that comes at the cost of a less evenly cooked joint or steak.
That's because the bone acts as an insulator, so meat close to the bone will be 3-5°C cooler than the rest of the joint – and consequently less cooked. Furthermore, because bone heats slower and cools slower than the meat, it can make “carryover cooking” a bit more tricky.
And what about stock? You'll need to break or saw up the bone to release any of the marrow and nutrients.
But there's no doubt about it, a bone-in roast certainly adds a bit of drama – and tradition – to any meal. And a T-bone steak just wouldn't be quite the same without that big bone. But don't expect any extra flavour.