Sorry to be so black and white about this, but I really feel that there are two ways to do this and one way is right. If you can't see my point of view on this I would have to say it's due to a lack of experience in the area.
Experienced and humble, obviously.........
I've been gigging for 20 years, and I've been in dozens of bands. I've probably auditioned for a hundred, and I've probably auditioned hundreds of potential different bandmates. There's one thing I've learned from my experience: there will be an interview first. When I am the one holding the auditions, I let the auditionee decide: they can either do the interview over the phone, or we can do it in person. But....they're going to do an interview before they waste my time in a formal audition. If they don't want to do an interview, they don't get an audition......simple as that.
Many factors can make even the best musician a complete waste of time: excessively busy schedule, utter stupidity, unreliable transportation, ego, attitude.......Any one of these issues can make this potential bandmate a complete waste of time and effort. Being able to play the music is one ONE part of being a good musician. Anyone with decent people skills can vette out these types of issues with a simple interview.
I could give dozens of examples, but I'll use the most recent. The last female lead in my band had a terrible interview. She was clearly pretty ignorant, was between "day jobs", and spent 5 minutes telling me about her alcoholic boyfriend. But.....she could really, REALLY sing. I discussed it with my band mates and we decided to giver her an audition despite our better judgement. At the audition she continued to prove that she would be unreliable. But....she could really, REALLY sing. We hired her, against our better judgement. The fun started right away. She constantly missed practice because she couldn't remember the dates, even when they had been given to her a few days before. She lost her day job. Her car died and she couldn't pay to have it fixed, so we had to transport her to gigs for a month. I ended up in a fight with her drunk boyfriend, in the middle of a gig, because he said I gave him a look (which I did, because he was trying to paw a 14 year old girl.) Despite her fantastic singing skills, we fired her, because all of the personal antics and drama were simple too much for the rest of us. Had we followed our instincts, we never would have wasted our time.
Adding a new member to a band is a significant investment in time. It behooves you to get to know as much as you possibly can about these people before you waste that time. Skipping the interview process is about as unprofessional (and ignorant) as you can get.
This works both ways for me. When I was looking for a band a few years ago, I responded to an ad that sounded perfect. I emailed the guy, and he emailed me back giving me an audition time and nothing else. I responded and asked him to call me. He did finally call, but he didn't want to talk. He said "just come to the audition and I can answer all your questions there." Because he refused to talk, I passed on the audition. A buddy of mine, however, went for an audition. He reported back that the band leader was a complete jerk and the band wasnt nearly as good as their ad led the reader to believe. None of them had gig-worthy gear, and they were expecting their new bass player to purchase a large amount of They also tried to physically intimidate him into leaving his gear for their guitarist buddy who was auditioning next (and didn't own a bass.)