To be fair, up until America earlier this month, Marvel has not often announced books without creative teams. At least, not that often in the past few years that I can recall.
Given that Marvel just announced six X-Men books besides Iceman without creative teams, though, it admittedly doesn't hold up so well anymore.
and it would be damn fine journalism to ask why that's the case.
It's much more likely they're trying to find an artist to pair with the writer who pitched the story, something that is difficult and a real part of the process, rather than just announcing things and scrambling to find people to write and draw books whose viability is historically in doubt.