Popularity absolutely does not impact the logical correctness of an argument: an argument is true by virtue of its own structure, if you say popularity somehow affects its correctness you've basically jettisoned logic in favour of subjective opinion.
At best popularity serves as a useful heuristic for when you don't have the means to carefully confirm the correctness yourself.
(There is a fairly uninteresting special case where the popularity of something comes in to the argument as a factual statement about the world.)
I think you are conflating popularity of an argument with popularity as part of an argument. For the former, it's easy to agree that it does not affect the correctness of the argument. But in the articles case, popularity is part of the argument: That it is especially worrying the speaker is uninvited for an opinion which is held by a majority of people, i.e is popular.
Another example of this would be if we were having an argument about what music to play at some event we are hosting. I might well use the popularity of some songs as an argument.
No, but something being expected is something else that is not inherently tied to the correctness of an argument.
As a concrete example: wikipedia has a long list of common but incorrect beliefs, all of which one should not be surprised to hear being said but will remain incorrect regardless.
The author clearly states that Abott's position was not relevant to the talk he was to present. Wether his position on admittance us congruent with progress in client science has yet to be adressed.
The popularity of the opinion was not being used to support the truth of that opinion, but to point out the absurdity of censoring an opinion that has that much popular support.
At best popularity serves as a useful heuristic for when you don't have the means to carefully confirm the correctness yourself.
(There is a fairly uninteresting special case where the popularity of something comes in to the argument as a factual statement about the world.)