BYOD device platforms don't work that way... they are typically sandboxed solutions housed in an app (like Good Technology) or solutions which use the native email clients on the device via a separate device management and settings profile that handles things like SSL certs, enforcing password rules, setting up email settings and allowing remote wipe of the corporate data. There is no interception of 3rd party app data or personal traffic (e.g. sms, email to other accounts, etc.). The one thing that is true and unique about Blackberry's platform is that they support many more device management features than iOS or Android. You can really 'lock down' a Blackberry with an ultra-paranoid device policy (preventing things like app download or even restricting usage of the built-in 'core' apps deemed unnecessary by the enterprise). BYOD device platforms only allow corporate administrators a small subset of these features.
Headline is wrong and misleading. CMAS is just an emergency broadcast message originating from the cell networks similar to SMS/text messages today but for broadcast rather than P2P. As stated in summary there are three alert levels of which the user can opt out of the two lower levels. This will be used for things like amber alerts (lowest level) up to high priority presidential alerts. It takes some time to get into phones as the baseband chip makers need to implement the protocol stack (Qualcomm, et al) and the mobile makers need to implement the UI layer. The carriers need to put the hooks in for message delivery and similarly the infra companies must implement the protocol stack in the core network/cell controllers. This is nothing but the equivalent of the TV/Radio emergency broadcast system that exists today updated for the times. Take your tinfoil hats off people.
E911 has dependencies on the technology used. For GSM operators (like ATT) there are two scenarios. 1. 2G Handsets do not need GPS (or in actuality A-GPS or assisted GPS) since a network based solution can use triangulation using cell signal strength to get an accurate enough position to meet FCC rules for E911. 2. Cell-based triangulation does not work on the 3G (UMTS/WCDMA) network, so the requirement to handset makers is that you need to include a GPS chip for A-GPS (GPS position data is assisted with some network signaling from the cell tower). Unfortunately due to cost / economies of scale you do not see A-GPS in all 3G/UMTS phones yet. The network operators work around this with a temporary 'hack' where you do a handover from 3G to 2G for emergency calls. Within the next year or so you should see just about all 3G phones in US with A-GPS. GPS for location-based services (and not just E911) is another matter and is a function of the device feature set & price point.