Trump did not want to lend legitimacy to a bullshit process.
Well, that stellar theory got him impeached. But we all know you don't really believe that garbage because if he were truly innocent, he would have allowed anyone and everyone to testify and prove it.
You do realize that there is a lag between indictment and trial date to both find and prepare witnesses and to gather as much additional evidence as may become available.
I think Pelosi is simply counting on more info becoming available from Trump's continued criminal activity.