There is change in difficulty. You have masks that you can unlock and activate before entering vision and it increases its difficulty and reward. With 5 masks active you can get 470 ilvl gear but so far no one completed whole vision with all bonus objectives.
If you go only for thrall it’s not so hard , for some classes cake walk .
But if you do bonus objectives and then go to thrall he gets stronger based how many corrupted zones or lost vision you have completed .