I think the primary difference with Bishop Paprocki calling out the politicians that he did is that the politicians he named were Catholic, and he was promulgating a decree that they were to be denied communion in his diocese until they publicly repented; I doubt he would have named them specifically if they were not Catholic. He was making an administrative decision for their good and also to set an example for the people in his diocese with a concrete action (denying them the Eucharist) that was within his authority to do, and something that according to Canon Law, that he is actually obligated to do.
In this situation, Trump is not Catholic, and the Archbishop’s statement was flimsy in it truthfulness, at best, and is essentially is just repeating a talking point that we hear in the media everyday without real, concrete evidence. I won’t say that it is necessarily wrong for a Catholic bishop to call out a politician by name, whether Catholic or not, but making a blanket accusation of racism that doesn’t bear on any specific moral issue or serve any purpose, other than to insult or attack the subject, is not what I would consider good form for someone in his position. There are other bishops, whether speaking about abortion, immigration, or something else, that manage to make their points without having to resort to name calling or insults.