Not only did I self pay, but went outside the country for my surgery, I expected resistance from doctors here when I returned home, and while some initially raised their eyebrows when they heard where I went and what I got, they usually have to agree they can't argue with success.
That said, my larger concern was getting my annual (or even more frequent initially) labs done, as well as dealing with anything that came up later related to my WLS. Years later, I did have some partial recurring obstruction, which isn't uncommon once we have lots of extra room in our abdomens for stuff to move around, as well as adhesions from any previous causing problems.
My regular pcp orders my labs with my annual exam, so they have always been covered by my insurance, and I've had 3 different insurers since my DS. All have covered my labs as they are just coded as intestinal malabsorbtion.
I had the adhesions/blockage taken care of at the same time my gallbladder came out (another common post op issue, so if your surgeon will take it out at the time of you surgery, DO it). There were plenty of scans and scopes during the blockages, and insurance paid for all, even when I had crummy insurance.