
From the Xbox announcement
“This change will not affect your ability to play Xbox 360 games or DLC you have already purchased. Xbox 360 game content previously purchased will still be available to play , not only the Xbox 360 console but also Xbox One and Xbox Series X|S devices via backward compatibility.”
Actually, the devs seem to respect the players. I’ve only once spent more money than the initial purchase and it was to add a rogue like campaign feature. There are micro transactions, but it is actually feasible to just play and earn everything. I have all of the heroes unlocked and most of the skill tree.
Edit: to add, I have the game via steam as well and the cloud saves go between both. Only needed to buy the rogue like mechanic once but base game each time as the rogue like is attached to the cloud account on their servers.