I guess he had to try to do something to soften the blow of the omnibus:
“WASHINGTON — Transgender troops who are currently in the United States military may remain in the ranks, the White House said late Friday, but the Pentagon could require them to serve according to their gender at birth.
The policy recommendation that President Trump approved flatly states that “transgender persons who require or have undergone gender transition are disqualified from military service.” But it also largely gives the Pentagon the ability to make exceptions where it sees fit.
The policy adopts recommendations that Mr. Trump received last month from Defense Secretary Jim Mattis. It comes after court rulings froze the president’s initial ban on transgender troops — issued in July — as potentially unconstitutional. …”
This is another one of Trump’s multitude of “yay, that’s a good headline” stories that starts a process that ends up later being called a foul ball by the federal courts. He can go back to his base and say he tried without the policy ever being enacted. See also the token gesture vote on the 20 week abortion ban.