The only rub I could see is how public the map would be and how easily it could be exploited.
For example, I have a smart thermostat I haven’t connected to the internet because I worry that usage data hacked at the manufacturer’s end would amount to a schedule and a roadmap to homes that are predictably unoccupied based on when the heat or AC are on. That’s an extreme illustration, but relevant.
Perhaps a voluntary disclosure form, including coverage direction and range, with limited access and a clear purpose for how and when it will be used would encourage participation instead of suspicion. We definitely wouldn’t want to create a public map of where cameras aren’t.
A friend of mine who still teaches at UK helped create this map years ago of private and public security cameras in midtown Manhattan. Something like it could be very helpful if an incident occurred. Designated admins would be able to contact individual residents to ask them to check their footage. I actually put out a similar call today regarding the tire dump in the alley. A map like this would have made it much easier to know who to contact directly instead of just a general request.