It's specifically intended for low impedance sources (like the signal output of an audio preamplfier or a power amplifier) and any JFET substitute here would be significantly noisier (about five times noisier for the OPA140 and about four times noisier for the OPA827 and LT1792). And for a bipolar op-amp in the ~1nV en class, the AD8597 actually has comparatively low input bias current and current input noise.

Not "noisier" but "the voltage noise from the datasheet is lower", nuance. There's also a current noise, and there's also noise from the input filter.

If its purpose is audio noise analysis, i.e. > 20Hz, so ok. But at low frequencies the performance of this schematic is not great. Calculations and equivalent noise diagram attached, I got 100nV/sqHz @ 1Hz and, it's true, about 1nV/sqHz at the asymptote.

Another nasty mechanism : With such a bipolar op amp the input bias current is about 100nA. Cf the datasheet on page 8 "Input Bias Current vs. VCM", it can be calculated the bias current TC is about 1nA/°C. When the input of your amp is short circuited, or when you connect a low impedance source, the non-inverting input of the op amp sees the impedance of your RC filter, about 5kOhms at 1Hz (28µF // 100k). Let's say there's a die temperature fluctuation at 1Hz with an 0.01°C amplitude, and there you have a new "noise" source contributing for 50nV/sqHz.

For very low noise AC-coupled application, bipolar amps are not the way to go. The design by Levinzon posted by awallin, JFET based, does better than this.