Agree the ex-ABN are too cheap compared to the N-S-T, both were not deemed "must pay" and the only difference is the timing of the suspensions.
The difference is probably caused by the fact that securities that are not current stay off limits for some institutional investors.

I switched all my G into S some months ago, at very similar current yields (adjusted by announced suspensions)
And now I'm slowly going back to G. Still half way in the return trip.
G have an adjusted 125 basis points additional CY at today's close. Could go down again under 25 bp.

The other striking spread is with the "must-pays". T or S are yielding 80 bp over the H-F "must pays". Both being current now, that spread should continue reducing, from over 100 bp to perhaps 25 bp.

I assume both will become subject of buy backs - liability management, much before any new suspension might come into the radar. Or is that wishful thinking?