He’s playing Ken now because he heard of the buffs Ken was getting in Ultra. Heck he was playing Ken @ Evo so he must’ve got early word on it.
Also it’s pretty obvious Momochi likes Ken, since he has mained him in every single version of SFIV.
SFIV - He played Ken @ Nagoya Street Battle 1, he later switched to Akuma and was one of the people who put Gouki on the map along with Tokido.
Super - He played Ibuki @ first, got destroyed in Godsgarden and than switched to Ken for the rest of Super, got 2nd @ a season’s beating with Ken, losing to Gamerbee’s Adon.
AE - Played Makoto seriously, than Ken, than Yun (kept Ken for Sagats) before switching to Cody because he didn’t want to get boo’d anymore like he did @ Evo using Yun… (LOL)
2012- Played Cody for a long time until he saw dem Ken buffs for Ultra and went straight back to Ken, will be Top 6 in the latest topanga league which is a big improvement on his previous topanga league placing with Cody.
Ultra - Lock in Ken.