>>725402157
Bowser Jr is a major character in Galaxy regardless. Still, due to the way the first movie is structured, and basically skipping Sunshine, I don't think they can feature Bowser Jr. (feigning) thinking that Peach is his mama.

Toadsworth's last original appearance was in Mario & Luigi Dream Team, back in 2013.
Since then he's only had re-appearances as either cameo inclusions (e.g. collectibles), or re-releases/remakes of older games (most recently Paper Mario TTYD on Switch).