To be fair, this was changed so that the AUDIENCE could know who it was.
For example, the 1980s movie Firefox takes place mostly in Soviet Russia, but everyone speaks English. This was done so the audience could clearly understand what was being said and what is happening. There are instances where it is simply assumed that if that particular situation was real, the characters would actually be speaking in Russian and not English.
For Star Wars, the audience could only assume the mysterious third Force Ghost was Anakin, but could have been confused as to who it was if they were not paying close attention or if they had missed some parts of the movie. After the prequels released, it could have been more confusing to leave it that way since the original actor looks nothing like an aged Hayden, so the actor was changed. There also could have been a likeness or royalty deal that needed to be renegotiated and it may have been faster/cheaper/better to simply have Hayden instead.
To be fair, this was changed so that the AUDIENCE could know who it was.
For example, the 1980s movie Firefox takes place mostly in Soviet Russia, but everyone speaks English. This was done so the audience could clearly understand what was being said and what is happening. There are instances where it is simply assumed that if that particular situation was real, the characters would actually be speaking in Russian and not English.
For Star Wars, the audience could only assume the mysterious third Force Ghost was Anakin, but could have been confused as to who it was if they were not paying close attention or if they had missed some parts of the movie. After the prequels released, it could have been more confusing to leave it that way since the original actor looks nothing like an aged Hayden, so the actor was changed. There also could have been a likeness or royalty deal that needed to be renegotiated and it may have been faster/cheaper/better to simply have Hayden instead.