The bearing still is still pressed onto the axle and it is still trapped solidly against the axle tubes, it just looks like it's moved inward slightly on the axle. The plate holds the seal and the seal holds the bearing. So yeah I guess the seal does get all the lateral pressure, but it's of a different design that the inner seals that you are referring to. I can take a picture of the seal if yer interested.
So needless to say, you can't mix the axles and housing from the two different styles that are obviously available on the '69, correct?