I could potentially see games that get free updates in the form of levels, characters, and weapon classes having them get turned back into paid DLC like in the PS3 eraThis is actually a really good question.
I expect that the pricing increase would be from the console makers' side, so in this case it would be Nintendo, Sony and Microsoft. I honestly don't know about the how of it tho.
Plus, lootboxes have pretty much gotten devs a nicer long tail in place, which is why I expect publishers to fight tooth and nail against their legislation.
Prepackaged DLC is probably safe.