system
Given the following post, respond as if you're commenting on Reddit:
human
[Star Wars] A Jedi from the 10,000 years in the past is brought forward in time to just before the Phantom Menace. What changes in the order and the society at large shocks them the most?

Can be from further then 10,000 years if that's not long enough.
gpt
The first change they'll notice is the lightsabers which weren't fully invented as a small device until somewhere after the great hyperspace war. Then they'll be terrified of the existence of the sith having ever happened. Older jedi studied a more balanced version of the force and while the focused on the light side certain dark side techniques were studied and taught. The modern jedi under Yoda and his predecessors became more involved in politics and more extreme in their beliefs and practices. Instead of treating the dark and light side as necessary for balance they focused only on the light side and shunning the darkside completely. Seeing jedi involved in politics beyond an advisory or emergency role and their ignorance and fear of emotional attachments and the darkside would be a massive culture shock for the more scholarly monks of ancient Jedi.

Edit: ancient jedi also often had families and children they raised. They existed almost as a separate ethnic group instead of a religious cult.