It had to continue to use phenotypic variation, because its ascospores limit gene exchange. A force propels the spores out of the asci. The force is created by shrinkage of tissue upon drying. Morel spores are very heavy, which allows them to function better as projectiles. They often contain more than twenty nuclei, which increases their mass.
Some spores stay on the surface of morels to be picked up by wind.
But wind is not used effectively by morels. Another problem with dissemination of spores by morels is that there are large amounts of space between localized populations of morels, because the soil must be sandy or similar, which is usually limited to river basins. There is a lot of diversity of morel types, and those differences are readily observed over distances of a few hundred miles. But spores are not easily carried by wind over those distances. Regional differences are sustained for this reason.