@Michael-Dallas
I work in the same industry as your friend, although tied closer to Microsoft than to Nokia, and also in Europe.
Anyway, your description sounds much better to me now:
he said carriers can add their stuff, but Microsoft limits what the carrier, in this case AT&T, can add/change; however, it's mostly testing to make sure the update does not crater the network.
Yes, carriers are limited. That is a far cry from being able to "do whatever they want (add/update/remove/etc)". But what are those limitations? They are precisely the things I mentioned earlier. Carriers can add any apps they want, but they can't screw around with the OS in any way. IMO that is a very big advantage over the "anything goes" approach of Android. It gets every WP device very close to being the equivalent of a Nexus device. I want people to understand that, which is why I jump on statements like the one you previously made.
Skype is somewhat special, as carriers may ask OEM's that the devices headed to their network don't come preinstalled with that app. The ability to satisfy that request is one of the reasons Skype isn't baked into the OS like other 1st party apps. If you consider Skype part of the OS (I do not), then you might think of that as "removing something from the OS". I would concede that point.
Just as your friend said, carriers get early access to updates so they can test the update on their networks prior to releasing it. I am unaware of any carrier doing anything to an update that goes any further. Finally, even those things that are specific to the carrier (like configuring carrier settings) are handled by the OEMs, not the carrier.
Otherwise your info is good, no need to lurk :wink: