Frank,
Welcome! Most of the tenant base in that location stem from Randolph AFB and employers in the periphery. Medium income around $45k-50k and mostly blue collar. You'll get many tenants who are families just moving into San Antonio due to PCSing or a job transfer and looking for an affordable option while they get rooted. Many tenants are drawn to small MF due to the affordability, employer proximity and lack of high-density as you will see with larger apartment complexes.
The answer to your question is yes, once the market is completely rented out and stabilized, those units will rent @ $1,250 per month during the spring and summer months, however, you'll likely see a dip in the fall and winter months if you're having to fill a vacancy. The issue with new development MF communities is that the first couple of MF properties to be finished and rented out will likely achieve rents suggested on the proforma. Where the drop-off occurs is when multiple properties are completed at the same time and you have multiple vacant units sitting on the market. In this situation, it becomes a game of chicken to see who drops rent first and it's likely the 1031 investor who came in at 40-50% down.
I would certainly stress to you to fly into San Antonio and tour the multifamily market before pulling the trigger.
Good luck and thank you for your service!