I wonder if D.C. would also get another Electoral Vote if Utah received one.
No it would not, DC gets 3 EV as deteremined by the XXIII amendment to the Constitution, an Act of Congress csn not chage that. Of course since DC is not a state it has had the privilege of getting 3 EV even though based on its population, it should only get one.
I favor allowing DC residents to vote for MD Senators, a Congressman, and to vote with MD for President, (as they once did in the early 1800s), and repealing the XXIII amendment. That way DC would get full represenation, get one Congressional seat in MD and thus they would not have any justification for having 3 EV under the XXIII.
Of course this would be a net + 3 EV for Republicans (Republicans +1 in Utah, Democrats -3 inDC, but +1 in MD),