I'm really glad the first FC I joined took me through coil. There are some pretty darn big plot revelations in there that I'd never have seen otherwise - including where in the F Alisae disappeared to for the entirety of ARR.
I doubt they'll ever make them required content, but even if they did they are super easy and probably wouldn't even take an hour to fully clear solo (maybe duo for some fights?) unsynced. Even savage coil can be solo'd now - I solo'd t6 and t7 savage as a dancer and was told 8 and 9 could be solo'd as a paladin. Just didn't try those myself :P