FOMO is damn near gone from Warframe now, aside from Baro. I’ve been playing for over 8 years.
Since Prime Resurgence, Nightwave rework, Baro Tennocon relay and cyclic event schedules. The only way to truly miss something in this game is to willfully ignore it.
I don’t know if there was another nightwave rework, but he one somewhat shortly after its release definitely did not change anything about the fundamental core issues of the whole thing. Baro isn’t new and prime resurgence sounds like yet another grind layer, but their description is too obtuse to really understand anything.