Would it be weird to cold email former students of a prospective advisor? I was accepted to a PhD program, and the two professors I mentioned in my application have reached out to me to discuss research. Now I am wondering what is the best way to gather information on them. Is it considered odd to cold email a recently graduated student from the program? Or current students? I'll likely be in the same community as these people for awhile so don't want to be considered strange ...
Basically, almost all the PhD advice I've come across stresses the importance of talking to an advisor's students. But how do I contact these people? I will be visiting the school but am not sure I will have time to both meet with all of the faculty I'm interested in and their students.
This is an opinion and you may get opposite opinions, of course. If it is weird, it is only a little weird. I think it is something worth doing, actually. "How is Prof X to work with? Does s/he provide a lot of help or only a little. Any thing I should be aware of?"

There is very little worse in doctoral education than having a poor or abusive advisor. All you really need to know is that they treat students appropriately, even if they are (very) demanding. 

You can find a lot of horror stories about advisors by searching/browsing around this site. 

But just keep it informal. 

I don't recommend cold calling professors, but would treat calling students differently.