Back in Tech Readout 3025 Revised, one of the downgraded SLDF 'Mechs was the MCY.98 Mercury, which dropped the MASC and Ferro-Fibrous armor for another ton of standard armor.
With Tech Readout 3039, though, when the Star League downgrades were revisited, the MCY-98 was not included, and the introduction for that section (written by Focht) mentioned that the Mercury did indeed die out during the Succession Wars and, as it (along with the Crockett and Exterminator downgrades) were no longer around by 3039, it was omitted from that section. I've also searched the Master Unit List site, and found no listing for the MCY-98.
Did the downgraded MCY.98 exist in-universe, and is it still considered a valid, canon design?
Thanks in advance.