I'm going alone next month.
Yes, you certainly are "brave" for going alone. Despite the fact that you aren't physically alone, you don't know the people around you from Adam. Many people need to have someone with them for their emotional security and to act as an advocate.
It may be easy for someone who thinks of this as old hat to say there's nothing special about traveling to a foreign country and putting your life in someone else's hands who you have never physically met before, but in all honesty that isn't a normal thing that most people contemplate.
To the OP - I feel your concern. I understand exactly where you're coming from. In my case, my wife had a gastric bypass many years ago so she is familiar with the process. She is very supportive of me, and honestly that makes a huge difference. We too have two children and the way circumstances dictate, she can't come with me to Mexico so I'm doing it alone. I've traveled all over the world. I used to work for an airline and we flew for free. My concern isn't the traveling part, but being in an extremely vulnerable position with no on-site support structure that you can absolutely trust.
Sure sure, don't get me wrong, I "trust" Bariatric Pal and the doctor and the support staff because this si the business they're in and I trust they'll do a good job. That isn't the same kind of trust I'm talking about. Not the same trust I have in my wife or my siblings.
The bottom line is this. In my opinion before you decide to make this decision you should have a firm support system. Preferably your SO, but if not through a support group or otherwise. Dr. Altamirano has a support group on FB and I guess some others do too. Even if you travel alone, you have got to know that people are behind you and will help you reach your goals.