People for some reason continue to wonder whether the eighth episode of "Star Wars" is named after one particular Jedi or a bigger number of them. Although there is only one Jedi, who is Luke Skywalker.
This is indicated by:
1. Yoda
2. The seventh episode introduction
3. Director of episode 8 Ryan Johnson back in August
For me, Jedi is used in the singular form. In "The Force Awakens" it is known that Luke went to look for the last Jedi temple. He is the last Jedi
4. Ryan Johnson again, that everyone finally understood