Theoretically there is nothing that limits you from having a modded forever-world as-long as the mods do get update per release.
However every server i created based on large mod packs has died within the year. The reason is simple, those packs are super complex and so is the risks for bugs, glitches and corruptions. Its possible to maintain the world, fix corruptions, ban problem-causing items/features. But if you or other players are even a tad to ambitions your gonna spend more time fixing the mods then actual playing.
Chances are also slim those mod-packs actually do manage to update without issues. If you want to keep the world for a long time i recommend as little mods as possible. Adding mods later is super easy, removing a single one can brick your world. Even if your world has only a single mod you may hit a road block. I am still waiting for thaumcraft 6 (Beta release was in 2019, since discontinued)