But they won't. Fortunately, Nokia can do everything it wants with Linux, including DRM, SIM locks, etc., and comply with GPL and even GPL3.
The key is knowing how to draw bright lines between different parts of the system. That's a legal term, and in this case it means a line between the Free Software and the rest of the system, that is "bright" in that the two pieces are very well separated, and there is no dispute that one could be a derivative work of the other, or infringes on the other in any way. All of the Free Software goes on one side of that line, and all of the lock-down stuff on the other side.