No person shall ... hold any office, civil or military, under the United States, or under any state, who, having previously taken an oath ... as an officer of the United States ... to support the Constitution of the United States, shall have engaged in insurrection or rebellion against the same ...
so, the 14th amendment requires no convictions. Confederates who were booted or barred from fed government did not get a trials where they argued about Northern aggression.
any conviction of Trump does not hurt the argument he engaged insurrection or rebellion, but conviction is both 1) not needed under the 14th amendment and 2) not relevant without the 14th amendment.