As long as you're running Bridge, you could keep AE open, and then replace the image.
If you've designed a template. I would recommend in AE using a pre-comp called a drop zone. A custom sized comp with guidelines / safe areas that is nested into the final comp. Then you basically can quickly drop any image into the dropzone composition, align/scale, and it will nest into the render comp.
If you dont want to run AE, having bridge running if you simply set a standard for the picture size, as in same size always, crop for import into AE, and then simply replace the photo file on the disk with the new one, using the same name, it will update on the PPro timeline.
As far as doing a replace command inside PPro, from a linked AE project, is not possible.