Very different market compared to when Telltale was last active. You can shit out anything you want and it'll sell more than previous games, as long as you don't get a smear campaign from outrage merchants of either side.

TWD > Dispatch = Tales of the Borderlands > Wolf Among Us.

it's not like they appeared out of nowhere, it was a group of devs known for making titles just like this to high commercial/critical success in the past that reformed after their previous studio went kaput.
>The same teams previous work combined the last 10 years don’t even equal half the sales.
every title these days is the fastest/best selling X title in Y days, the userbase has simply grown exponentially over time. that said it definitely helps that people have been starving for a new telltale-type game that was, you know, actually fucking good.