So McConnell just sent out the procedures for a Senate trial if Trump is again impeached by the house... and well, this is why I think the exercise is pointless. According to the timeline laid out, the Senate would most likely recieve the formal notification of the impeachment of the President on the 19th of January, and according to Senate Impeachment rules, would not be taken up until 1 pm the following day, which is the twentieth. Given that Joe Biden will be President an hour before that, that makes Trump no longer president when a Senate Trial begins.
Now McConnell does note that it could be considered earlier, but only given the unanimous consent of all 100 senators to conduct business out of normal session. Which is... not likely.
So I fail to see what this little excercise in pointlessness actually accomplishes, if the Senate cannot remove Trump from office, because he will not be in office by the time they start the trial. For the record, McConnell isn't slow walking this at all, this is the earliest he could possibly act on it (Not doubting that he wouldn't slow walk it if he had too, but he doesn't need to do so here). I believe the Senate could still convict Trump after he is removed from office, but the only result of that would be disqualification from further office. Which might be worth doing if it had a chance of passing, but it doesn't.