Adjective-Denoted Nationalities without "the"
Does that mean I can refer to adjective-denoted nationalities without "the,"
No.
This is journalese and is usually limited to headlines. It also requires a certain form of context.
- Conversation
Hello John.
Hello Mary. Can you tell me a fact about France.
French love good food. (incorrect)
The French love good food (correct)
- News story
French love good food says Macron!
When being interviewed last night, president Macron was asked what he liked most about being French. "We the people of France, love good food!" He proclaimed.