I think it can be used the two, depend on the sense.
in the wind
Likely to occur; in the offing: Big changes are in the wind.
in the wind about to happen
in the wind imminent, coming, near, approaching, on the way, looming, brewing, impending, on the cards (informal), in the offing, about to happen, close at hand By the mid-1980s, economic change was in the wind again.
on/into/down the wind Nautical
In the same or nearly the same direction as the wind.
For example, some fungi and liver flukes can make ants climb to the tips of grass stems before dying, so that the spores can be dispersed on the wind or the flukes could be eaten by another host - a bird.
"I am a leaf on the wind