Is the organizations memory so short that they've forgotten the not so distant past of pre-2005 city lay outs which used the 3-4 inner rings rather than four spokes as the cities theme camp placement area?
How can you run out of space when you just need to annex one more ring to get everybody in? It's not like the number of people camping changes somehow.
Perhaps the Burning Man org has achieved their 2005 "spoke plan" goal of integrating the suburbs, but had never planned on the "what if" of having achieved their goals. The unforeseen "what if" of course is that more people apply to be theme camps then ever before.
Reference:
Map 2004: A,B,C, and part of D are "theme camp/village zones"

2005: 4:30 and 7:30 major spokes, 3 and 9 keyholes, 2 and 10 half spokes: