The only mention of "priority communications requirements" in the Executive Order is:
Sec. 5.2. The Secretary of Homeland Security shall: (a) ...
(e) satisfy priority communications requirements through the use of commercial, Government, and privately owned communications resources, when appropriate;
It's not associated with "in conditions of crisis or emergency" (though that phrase turns up elsewhere in the EO 4 times). Notice it's not actually about 'grabbing hold' of anything; it's about making sure the government can satisfy its requirements. If you're paranoid, you think this means the evil government is coming to seize your frequencies; if you're normal, it means they'll pay for it, or make sure the Emergency Alert System still works.
If there is something in the EO that is significantly different from the situation before it was issued, then the author ought to do soem damn work and tell us what, rather than picking phrases out at random and claiming this is a power grab.
Here's the 1984 version, for instance:
The NCS shall seek to ensure that a national telecommunications infrastructure is developed which:
...
Is capable of satisfying priority telecommunications requirements under all circumstances through use of commercial, government and privately owned telecommunications resources;
http://www.ncs.gov/library/policy_docs/eo_12472.html