A few things come to mind regarding cans vs pouches. I have little experience with pouches, but a lot with cans. Just before I left my previous role as the TM for a cannery we were looking at getting into pouches and these were some of the issues we faced.
As previously mentioned cans are more robust so can be retorted without over pressure, and generally can withstand more variances in the retorting process and general handling by the operators/line staff.
Cans can be filled and sealed faster than pouches, so greater throughputs per hour. They can also be moved around and the factory easier and faster, they stack on top of each other without the need for cartooning first etc and they can be stacked higher than pouches. Allows you to maximise the storage space available, we had a very tall warehouse, it was not unusual for canned goods to 3 or 4 pallets high, no way could you do that with cartooned pouches.
Cans have a much longer shelf life than pouches. Pouches are usually restricted because of oxygen transfer rates affecting the quality of the product.
Cans are labelled post production so you can have a variety of labels for the one product dependant upon the customer base, exporting for example as opposed to a local market. So you can make now and label to order later, handy for seasonal products or for product that does not quite conform. Have a label that is lower spec (i.e lower percentage meat/fruit or whatever the typical non conformance is) and sell it to the "not quite right" type outlets. Better than dumping, at least it could recoup the costs. I suppose this is along way of saying you cannot relabel pouches.
Hope that helps.