I also think that nothing will become of this 900MHz site.
Awhile back I was perusing the LCRA site and was searching for customers of their radio service. I came up with a comprehensive list by County, and included the list in the LCRA Wiki page I created. I made the assumption that since AACOG, Bexar County, City of Fair Oaks Ranch and SAFD were customers, that these (900MHz radios) were going to be utilized, if needed , to support a mutual aid fire situation or to assist Kendall County/Boerne (since Fair Oaks Ranch is out that way, almost to Kendall County). That is the only reasoning I could come up with.
With SAUA coming in to play I'm hoping we can confirm a test between SAUA+LCRA (those two are definitely linked) +SA EDACS (an analog talkgroup, not PV). If we could catch a test between these 3 systems it'd be an almost certain bet that nothing would become of the SA 900MHz site. This would give San Antonio a back gate to P25 interoperability with Austin. However, besides being able to patch an analog EDACS talkgroup to another analog EDACS talkgroup (SA>LCRA) I wonder if San Antonio is going to try to fulfill any other interoperability "requirements."
As I posted in the new LCRA thread, an NBFD Asst. Chief indicated to me that it looks like the majority of AACOG will go VHF P25 TRSs and that New B would follow AACOG. How San Antonio will influence this I don't know.