I'm not sure if I exactly understand your solution. Would you be lightly squishing the contents of the bag with the spring plates while sealing the front?

It also seems possible that manufacturers wouldn't want chip bags to look comparatively "deflated" when sold in a same-pressure environment (and thus stand out less on the shelf compared to competitors'). Also, maybe bags rupture for reasons other than pressure change and thus a stronger seal is still desirable. Just guesses, though I know the article didn't make mention of any of those reasons.