Well, it's difficult to tell. There's a possibility that it's real, but there's also a chance it's made up for entertainment or to convey a certain message. Without more information, it's hard to be definite.
Lore can be seen as the back story. It might include details about the origins of a place, the past of characters, or the hidden histories that shape the current situation in a story or game.
The Lore TV show is indeed fictionalized. It takes elements from various sources and weaves them into fictional narratives that may or may not have real-world inspirations, but are not based on actual events.