In the lecture at the point in the image, instructor changes the PlayerLocation to Player, and changes the variable type from Vector to Object.
He then sets the type of object to Actor and then says
"… we can change the baseclass to Actor - though that’s not particularly important … "
If you do NOT change this base type to Actor, at least in Unreal 5… you will not be able to set the rest of your BT nodes to the new Player. They do not want an Object type. You HAVE to change that type to Actor as in the lecture.