Air is constantly moving and there's a lot of it, and so to have a measurable impact, this would need to be a pretty large region and/or evapotranspiration would need to stop for an extended period of time.
Plants have a greater impact on their environment than what can be measured through evapotranspiration
Evapotranspiration affects energy balance, which means that sunlight also plays a role in the ultimate effects.
The result is a rather complex web of interactions and an effect that would be very different depending on season, region, and how the loss of evapotranspiration occurred. So, the two scenarios you proposed would have very different effects.