If its satisfying then great. If its just a cash grab to drag out to 3 seasons, then it will harm the quality and storytelling.

They could go wither way, just telling the existing story but padding it out and filling in details not necessary for the game, or start telling new stories with new characters in the world.

Either can work but it can go wither very quickly. I have more faith in HBO than others but they have changed their policies in recent years.