The appropriate SNR is stated just below the 139dB. It's not recognized as such because it doesn't have the SNR nomenclature.
Your post has merit, but it seriously lacks tact.
AMB lists both the full spectrum, and the 1KHz. All the information is there in the screen capture in the posts above. I don't understand this nitpick, and the force by which the nitpick is presented. The standard measurement is noted there, and the odd one. The SNR @ 1KHz is more similar to dynamic range @ 1KHz, but not quite.
Yes, you can specify A-weighting to a single frequency. The A-weighting curve are dB adjustments at different frequencies. @ 1KHz the adjustment is 0. Measuring a 1KHz tone would be the same, regardless of weighting as all weighting scales that I know of apply 0dB correction at 1KHz. dbA, dbB, dbC are all 0 dB adjustments at 1KHz. It makes stating dBA for 1KHz pointless, but it's not incorrect.
My suggestion, make a DNR measurement and rename it. Also add SNR to "noise level" so that people's eyes can "pop" to it. Some folk see SNR, not read the qualifications of it, and go bat **** crazy. Fully qualified SNR is better than some unqualified SNR that leaves one wondering what was actually measured.