Gianluca IV. wants to tie the military even stricter to its government than before.
At least, that would be the only explanation, why he wants to change the oath, every soldier has to swear on and implement a "Königsgruß"-("King's greeting")line into the oath.
Making the Königsgruß an obligatory greeting in public met a big opposition in Königspalast already, even in the Leader's own party, so it's questionable, if he can succeed this time.