Trum has fired preemptively the head of the National guard for DC

"Head of D.C. National Guard to be removed from post in middle of inauguration"
The Army general who heads the D.C. National Guard and has an integral part in overseeing the inauguration said Friday that he will be removed from command effective at 12:01 p.m. Jan. 20, just as Donald Trump is sworn in as president.

This is the person that is a large part of the security for the ingratiation. Its extremely unusual to change commander in the middle of a mission. If something was to happen after hes sworn in would Trump be able to trust an Obama appointy to protect him ?

Trum has fired preemptively the head of the National guard for DC

"Head of D.C. National Guard to be removed from post in middle of inauguration"
The Army general who heads the D.C. National Guard and has an integral part in overseeing the inauguration said Friday that he will be removed from command effective at 12:01 p.m. Jan. 20, just as Donald Trump is sworn in as president.

This is the person that is a large part of the security for the ingratiation. Its extremely unusual to change commander in the middle of a mission. If something was to happen after hes sworn in would Trump be able to trust an Obama appointy to protect him ?

Finally found one account that mentioned a possible reason (FoxNews):

The Post reported that there have been contradictory stories about the behind-the-scenes developments leading to the decision.
A person close to the Trump transition team reportedly said transition officials wanted to keep him, but the Army pushed for a
replacement. Schwartz reportedly said the orders came in an email from the Pentagon. He will be replaced by a brigadier general
at 12:01 p.m.