The Spanish market was given a UHF allocation from the start, as 9 was, in the beginning, intended to be educational TV for San Antonio. However, there was precious little movement to getting it on the air until 41 started casting eyes at the frequency.
IIRC, the fight was between the educational TV supporters and the folks who owned 41. You can't blame the folks at KWEX/KCOR. Here they had been assigned a UHF frequency, reaching precious few Spanish-speaking folks in one of the largest Spanish-speaking markets in the country, when this nice, ripe, VHF was sitting there completely unused. It took quite an effort on the part of the people in San Antonio and Austin to save 9 for educational broadcasting. Of course, support from the University of Texas didn't hurt (which provided studio space in Austin) and I'd be surprised if the Johnson's didn't have a hand in it either.
The Spanish-speaking market in SA got screwed, IMHO, but in the place of a VHF voice for them we wound up having two very strong PBS stations in the area.