Fired? Maybe so. I was on the edges of some marketing stuff, and folks were indeed worried about slipping from #1 to #2. I thought there was less concern if #2 slid to $3, but I could be wrong. I don't think anyone would have been fired where I worked, but their careers may have gone south. I was there when Pampers slid to #2, in part because we also had Luvs at the time. As I say, I was on the fringe, but I was not aware of any panicking.
It reminds me of the Ford-Chevy light truck story, Ford leads Chevy comfortably, but if you add GMC, GM makes more light trucks. Does GM care that their share is split?
Is Pepsi that worried so long as their sugar free brands are growing faster?
I just looked at the five year stock chart for both companie, which of course is a gross check, and oddly their stock returns are almost identical over that period. It could be Pepsi has made a strategic choice to emphasize sugar free perhaps understanding Pepsi would slide in share, I don't know. And of course, maybe they react with more marketing and recover the #2 spot fairly quickly, or decide it's not worth it.
Should GM stop marketing GMC trucks to perhaps be able to claim the #1 spot? I doubt it. I think some folks prefer GMC to Chevy for whatever reason.