the current rear hub with 8 speed cassette might not permit a 11 speed cassette … some will permit a Shimano 11 speed MTB cassette with a 34t or larger big cog - but it can vary … ???
so - a new rear wheel might be required - or a new rear hub / freehub
so there is that
the crankset should generally pair or match with the rest of the drivetrain (including cassette) … so there is that …
My plan is to stick with a 11 speed and from my research and talking with my LBS I can go with a 11 sheep and not have to change the Hub or rear wheel.