My assumption was to try and make the troops look more menacing as a message to places like LA, really hoping for an NK dear leader style ass kissing but just got to hear the squeaking of a Sherman instead.

¯\_(ツ)_/¯

Last time they did a parade was back in '91 after the first Gulf War, they wore a combat uniform then as well but also wearing their LBE

But that was just after the ending of actual major combat operation, so it wasn't entirely out of place to wear the desert uniforms that were worn for that particular theater of operation

I'm not sure why they chose combat uniforms for Trump's parade, maybe Trump requested them or it was a bargaining olive branch to the troops from the brass to try to keep participation high since dress uniforms are much less comfortable to wear in parades and require more effort on the part of the soldiers to prep

I know we always did our best to avoid those kinds of events that required them