Hasn't 911 location been shared via gps location in pretty much every cellphone for the past decade?
I remember shitty verizon kyocera clamshells advertising gps for 911 in like 2004.
> Wireless network operators must provide the latitude and longitude of callers within 300 meters, within six minutes of a request by a PSAP.
> Code division multiple access (CDMA) networks tend to use handset-based radiolocation technologies, which are technically more similar to radionavigation.
> Mobile phone users may also have a selection to permit location information to be sent to non-emergency phone numbers or data networks, so that it can help people who are simply lost or want other location-based services.
Presumably Apple is going to share their Wifi-assisted data instead of raw GPS signal or radiolocation data.
Looking at my location in a dense urban zone, 300m would narrow my location down to roughly 300 houses. Good enough to get emergency services on the way, not nearly good enough to render assistance if the caller can't speak/doesn't know where they are.