It wasn't overwhelming. I think it was 44-38 for Biden. I think it's as likely to be a race thing as a woman thing (and is probably both), but there's also the additional factor that Kamala doesn't have the same long track record as Biden in this area, and doesn't have the same blue-collar Scranton roots.
I'm not sure Teamsters' endorsements mean much any more. I think the members will probably vote for whom they like, regardless of what the union says. It's like newspaper endorsements -- they used to matter, back when information was much more limited and so people looked to intermediaries like newspapers or unions to guide them. These days? If you think that states are killing babies after birth, who the fuck cares about what your union boss says? You need to vote for Trump! And if you know that's not happening, then you know you need to vote for Trump's opponent since Trump's brain is more mushy than ever.
On the margins, this might make a tiny difference but I doubt it. There are only about 1 million teamsters worldwide. For sake of discussion, let's assume they are all here. That would put maybe 20K teamsters in PA, on the back of my envelope. Maybe 30K. So how many of those votes would be changed by a union endorsement? 5K? That seems pretty high to me. 1K? I mean, I don't know, and obviously 5K isn't nothing. But it's also not likely to be terribly important.