I think you're right - the only way to do Dragonlance these days is to drastically update the original story, with sweeping modernizations to the cultural diversity. (And just tell purists to SHADDAP). If I were them, I'd reboot the whole thing and just make the adventure an update of the War of the Lance, like how Curse of Strahd repeated the original Ravenloft adventure, only one step further.
With all of that, I'm not entirely sure why they'd bother, though I expect that product would sell quite well, (I'd buy it), so maybe it would be worth it.