What makes you say that? Yoshi-P has expressed that he wants to bring in as many classic Final Fantasy jobs as possible--not just those from FFXI, but also ones from earlier Final Fantasy games.

Frankly, the class/job system makes it far more likely that we see more jobs than not. They've already discussed second jobs for each class. At the launch of ARR, there will be eight classes, which means when they roll out second jobs, we'll have sixteen jobs. Each new class they bring in from there will introduce two more jobs. The addition of blue mage seems more of an "if" than "when" to me, but maybe I'm optimistic.