> NTRU Prime (sntrup) is there mostly as a quirk of history (mlkem wasn't available when SSH went down the road of doing PQ).

ML-KEM (originally "CRYSTALS-Kyber") was available, it's just the Tiny/OpenSSH folks decided not to choose that particular algorithm (for reasons beyond my pay grade).

NIST announced their competition in 2016 with the submission deadline being in 2017:

* https://en.wikipedia.org/wiki/NIST_Post-Quantum_Cryptography...

TinySSH added SNTRUP in 2018, with OpenSSH following in 2019/2020:

* https://blog.josefsson.org/2023/05/12/streamlined-ntru-prime...

SSH just happened to pick one of the candidates that NIST decided not to go with.