I see it's common practice for brides to ask for references from previous brides, but I wonder if that's really bothersome for a previous bride?
The vendor could easily give you the names of a relative or good friend that would vouch for them no matter what, making the reference irrelevant.
I think it would be just easier to read reviews. As long as I didn't see anything negative (which will likely pop up faster than a handful of good fake reviews), then I'd have little cause for concern.
I can't imagine being a newlywed fielding calls from anxious brides wondering if their vendor is any good.
Have you had to respond to vendor references?