Their marketing is based around that sound... So it probably is seen as a big deal to them. Probably some pop-psych idea around having that sound be associated to them through the commercials and usage.
I've never heard a pop during a lifetime of probably eating my bodyweight in Pringles. Either it's always been purely a marketing thing and they're finally actually engineering it into their packaging, or people are attacking Pringles lids in a way I do not understand.
Same - I've literally never heard that "pop". I grew up thinking it was just their slogan, referring to the act of opening the tube (as "pop the top/hood/etc" is used for many other things), not onomatopoeia.