Jiyi I could maybe see a case for (though I'd rather see Noritomo Helmer for the Gyrfalcon), but are we really scraping the bottom of the barrel of notable MechWarriors that we'd have to trot out Othar for Legends II? Also, I don't think he even pilots that Blood Reaper anymore; he lost it in Redemption Rites.
Well, the Empire makes more of Blood Reapers, losing one shouldn't be a big deal. And many pilots have piloted different mechs in their careers. I don't think a pilot's current mech matters for which gets featured in Legends. Aris Sung's initial Stinger was featured rather than the Wraith he is far more famous for, and Phelan moved to different mech later on in his career yet his Wolfhound was featured.
As for the notable pilots in the book, Legends I had pilots like Damien Lucille "Lucifer" (only featured in very limited amount of fiction), Katherine Steiner-Davion (despite being anything but a mechwarrior really), and new characters we haven't seen in action at all like Trenton Marik.
Othar as the Wolf Empire's leader is a notable person and a mechwarrior, and will most likely have a large role to play in the future, so i see him as a very likely candidate for Legends II.