Though the source of the celebration is attributed to what you described above, it has evolved to one of a family gathering to give Thanks for all we have. I am sure similar occasions are celebrate around the world,
no Indians nessacery.
Sure there is a mythology generated to support the event. What country does not have a mythology to support a common narrative ?
But let's understand something, very few , if any people on America , other than children in school, think of Indians, or the Mayflower on Turkey day.
By the way the late comers on the Mayflower arrived in America in 1620 When St Augustine was thriving and was Founded: September 1565 , while the pilgrims were poking hontas, the Spaniards were building this in St Augustine Florida and it is only due to changes in history, and a different narrative . that we are not celebrating Matanzas day.
Castillo de san marcos built 1672