Perhaps.
But, "all of the Indians" would have been a lot of them.
I'm more than a bit skeptical that God would have allowed it to come to that regardless. Perhaps in the case of the more ruthless and blood thirsty amongst them. But I don't think so for the more 'benign' amongst the tribes. God has clearly reserved utter extinction for the very ruthless and blood thirsty throughout history.
That gives us something in excess of a 90% death rate.
Around about 1648 (and I think this occurs over a 3 year period) the Mohican Indians lost about 98%+ of their population. The Iriquois lost but 90% and thereby won the war with the Mohicans by outnumbering them.
So who is it God saves utter anihilation for?