Didn't Griner already play for Dallas in 2008?...
No wait, that was Gerald Green. My bad. I always get those two confused.
Yes, I know... sick joke I've been stretching out for 5 years.
As others have said, if anything it would just be a publicity stunt... like when Cuban signed Rodman for a handful of games.
It would, unfortunately, be damaging to Griner's career, though. She wouldn't be good enough to even hang with the guys in the D-League. She'd be absolutely dominated. And the WNBA is desperate to have the illusion of a "superstar"... Griner could be the Kareem of the women's league. That image would be toast (in addition to whatever little credibility the women's league had) if Griner inevitably embarrassed herself getting dominated by men.
It's not a sexist thing, I'm sorry to say. I've seen with my own eyes Division 1 Women's bball players get dominated in pickup game by a bunch of 5'8 white dudes who couldn't make their high school team. Granted, they weren't on the level of Griner.. but the gap in talent/ability/athleticism is almost unmeasurable.