This phrase is not literal. It means sharing news with joy and enthusiasm, not shouting from actual rooftops. She finally got her dream job and wanted to shout it from the rooftops.
Pro Tip 2/3
Emotional Context
Use when expressing a strong positive emotion about something that you're excited to tell everyone. When they won the competition, the team wanted to shout it from the rooftops.
Pro Tip 3/3
Informal Usage
It's an informal phrase - not used in formal writing or speech but great in casual conversations. We're engaged! I want to shout it from the rooftops!