Despite Brin's reemergence, several employees told CNBC they're doubtful he could adequately run what has become an increasingly larger and complex corporation.

Employees said that although Pichai didn't strike them as particularly visionary or as a wartime leader, it's hard to find someone better suited for the job, given all the complexities of Alphabet. The key quandary remains: move too early and risk widespread criticism; move too late and risk missing the boat.