I suspect that CA has already drawn up its development plans for the next year, and have fully allocated its resouces (people) to the various projects:

RTW Expansion
Spartan Total Warrior
Successor to RTW

It create patch 1.3 for RTW they would have to take people off these projects, which would delay their delivery; some of these existing projects deadlines may be set in stone. Also, they would not earn any tangible revenue from another patch, although they would get appreciation from many RTW players, which could have intangible benefits in the future (better sales of forthcoming products).

So, for a CA project manager, this could be a difficult decision to make.