This prolly a joke but I'm aware there's a lot of people who always believe in more continents for some reason, so I'll go ahead and explain it.for more continents? lol
Additional content like more nether stuff, more end reworks or even the ocean content has to be world painted. It doesn't mean stuff gets reset or even that there's going to be new continents, it's just the existing continents get expansions on content .
This all being said, there are scenarios where additional continent makes sense like if Mojang gave us basically 13 new biomes.
(Note: I'm just using a lot of examples, of if we were to rework these things it would basically be through world painter almost always cause they so big.)