Which do you think is easier?
Noticing that the center of the moon has been ripped from the core and moved to earth, or noticing that someone somewhere in the entirety of the world has summoned the Gedo Mazo out of the moon hundreds of thousands of miles away to an unknown location?
It's much easier to notice from the moon than it is from earth.
still no warning to earth that mazo seal has been broken.
still no warning to earth that mazo seal has been broken.
Toneri wanted to destroy earth because he misunderstood Hamura's wish.
Why would he warn his enemies?He tried to bombard them all.
It was likely 1000+ years later.
They anticipated Kaguya's return, and when it didn't come in their lifetimes, or their children's lifetimes, or their children's children's children's children's etc. lifetimes, they likely figured she was gone for good.
...plot no jutsu?if gedou mazo(juubi vessel) can be summon why does hamura need to stay on moon to guard the mazo if it can be summon on earth?
...plot no jutsu?
He protected it from outside.
And no1 could get near the Gedo because Otsutsuki guarded it
While Madara summoned it with Rinnegan!
So there was no need for him to go there,and no1 except Kishi predicted some1 could do that(unlock Rinnegan and break the seal).
If Madara would've gone to the Moon,Toneri with Tenseigan vessel Energy would've said :Hi,die.