It could be the opposite. Wells Fargo has a lot of different apps that need to authenticate and integrate with their identity management/sso system. It is near-trivial to implement this sort of thing, but it isn't necessarily trivial to make it fast.

I wouldn't be surprised if the authentication process was taking long enough that a decision was made to add some sort of "loader" like this to make it appear like the extra time was absolutely necessary from a security standpoint.

It's a bit of a lazy decision from a UX standpoint, but it isn't entirely uncommon either: when you notice some action is slow, slap an animation in front of it.