I don't have any inside information, so this is just a guess...
In the application for K259AJ, it is stated the existing antenna they are moving to on the same tower is the primary antenna for KROX-FM 101.5 and the auxiliary antenna for KLBJ-FM 93.7 and KBPA 103.5. The application also states that an application will be filed to move K274AX 102.7 to the same antenna.
It seems like they are trying to consolidate antenna locations and leases, either for cost and/or operational reasons.
I have no idea what the current condition is of the antenna for K259AJ, but this moves it down the tower about 45 ft at the same power and generally speaking a combined antenna doesn't perform quite as well as a dedicated antenna. The end result though, will likely be very close to the current signal.
In the case of K274AX, it is actually moving higher so the current ERP of 240 watts will likely be slightly lowered. That application has not been filed yet.