Pronunciation of корабль and ноябрь

Okay, there's the elephant in the room nobody seems to address. Wiktionary says these words are pronounced [kɐˈrablʲ] and [nɐˈjabrʲ], but no Russian ever pronounces them like that. Everyone says [kɐˈrabəlʲ] and [nɐˈjabərʲ], as if there were a short vowel after b (like кораболь, нояборь). Why everyone ignores that sound and no one comments on it? Maybe there's some rule in Russian phonology that explains it? There must be a reason, nothing in languages happens 'just because'.