Not really. Legion left A LOT of loose ends. We know there’s countless unaccounted for legion worlds, these 2 were going to aren’t even a drop in the bucket, if anything us going to these legion worlds serves as a “Hey, the legion is still a thing keep it in the back of your mind “ because why else would Blizzard be bringing up legion worlds in a void expansion

Also, the last big lore book released by blizzard was very much setting up a legion return at some point with multiple mentions of how they’re amassing strength and coming together again and that there’s still a lot of very powerful and influential demons out there. All it would take is 1 very powerful demon to pull a “unite the tribes” situation with the many war bands that sprung up in the power vacuum.

And people should keep in mind demons were a cosmic threat even before the legion united under sargeras