[ASUfool]

Could one have two white bishops after promoting a pawn?

[umanwizard]

Yes it's theoretically possible to have two light-squared bishops due to promotions but so exceedingly rare that I think most professional chess players will go their whole career without ever seeing that happen.

[da_chicken]

Outside of playing a game for piece value? No, not really.

In this case, of course, someone moved their bishop from black to white and their opponent didn't catch it until awhile later.

[IanCal]

Promoting to anything other than a queen is rare, and I expect the next most common is to a knight. Promoting to a bishop, while possible, is going to be extremely rare.