“Proclaimed on the housetops”
What you have spoken in the dark will be heard in the daylight, and what you have whispered in the inner rooms will be proclaimed from the housetops. (Luke 12:3 BSB)
What it sounds like today
Shouting from rooftops sounds like odd, theatrical behavior.
The cultural key
Houses had flat roofs reached by outside stairs: working, sleeping, and social space, effectively a second street level. News, announcements, and neighborhood alarms genuinely traveled roof to roof; the housetop was the village's public address system. Same rooftops, reversed direction. In Matthew it is a command: broadcast what I taught you privately. In Luke it is a warning, following 'beware of the leaven of the Pharisees, which is hypocrisy': your own whispers will end up broadcast. The village public-address system works on secrets too.
Recovered meaning
The teaching you're receiving privately is not esoteric secret-keeping; it's pre-publication. When the time comes, broadcast it from the most public platform a village had.