Could the power supply of ADA4899-1 be ±2.5V? Thanks!
Yes. You can use ADA4899-1 at ±2.5V supply. However, you have to consider its IVR which 1.3 V away from supply rails. So for this condition, the usable input range would only be ±1.2V. Same goes with the OVR. Regarding these trade-offs, if your signal of interest is within specified operating range, then ADA4899 at ±2.5V would not be a problem.