Is it true that a soda can or a bag of chips will pop in a plane at high altitude?
Not likely.  Consider how food products normally make it to you.  

Any competent US maker of soda or chips will design their product to be shipped 


on Interstate 70 or 80, via Sherman Summit (8650') or the Eisenhower Tunnel (11,158')
or more likely by rail, via again Sherman Summit (8015') or Moffat Tunnel (9239').*
Aircraft are pressurized to a pressure altitude of 8000' typically, so Sherman Summit (rail). 


If a food manufacturer were to botch their packaging, they wouldn't have your problem of a soda can bursting, they'd have an entire container load of sodas or chips burst and ruined for sale.  That is simply unacceptable, so manufacturers have a big incentive to get this right.

Other markets will have similar issues - the EU has the Alps, and China and India have the Himalaya. It does not apply to regional sellers in flatland areas, so a regional/indie Florida chipmaker, all bets are off. 

It does, however, apply to soda manufacturers, whose cans must endure extreme temperature (e.g. solar loads in a car) also in high places.



* Tennessee Pass (10221') doesn't count, it is weedgrown, rusty and cut in several places, being held for future capacity needs.