As most Earth customs have lasted for thousands of years, I can't see why things would take such a left turn that they would go away entirely or be put in some kind of blender.
We only THINK they have lasted 1000 years.
Isn't it possibly that if a Jew from 4000 years ago suddenly appeared in a synagogue, they might not even know what we are doing?
The Catholic Church has made numerous radical changes from even just 60 years ago.
1000 years ago, a lot of the Christian sects that are out there now, did not exist.
I mean really think about it.
Valentine's Day, Halloween, Birthday celebrations, Christmas celebrations, Yom Kippor, Rosh Hishona, Hunakkah,
Some of these weren't even celebrated 100 years ago!
How about all of the stuff Pagans celebrate today, they think they are celebrating ancient stuff, most likely not.
Culture is very fluid.
I find the stuff they do in the shows so silly.