A status update for FNAB Redone has just been released! You can read it here.
Viewing post in Five Nights At Baldi's Redone comments
Yes, that's where the Shadow Baldi character planned to be added to FNAB Redone originates from. While he was only an easter egg in FNAB Remastered, in this fangame he will do more, such as the amount of Shadow Baldi hallucination heads increasing when his AI is set to a higher level.
Also, the Shadow Baldi character in FNAB should not be confused with the character of the same name from the Baldi's Fun New School series, who has a different appearance and mechanics. In Baldi's Fun New School Ultimate, I'll probably end up changing Shadow Baldi's name at some point to avoid confusion with FNAB's Shadow Baldi.