I think a second time would be devastating.
Some will catch fire in the wild just because that's simply what can happen with smartphones, but beyond that, if Samsung has another widespread problem that results in another recall, well... I myself will walk away from Samsung. There is no excuses for this to happen a second time with back to back flagship releases.
Luckily, as you said, this is highly unlikely to happen. Now, Samsung has the industry leading battery QC-ing process. If you read the details about their new 8 step program, it's actually pretty insane (again, my point in the other thread: I know of no other OEM that tries this hard to learn and improve as well as Samsung does.)
But we'll see. Anything can happen!