Just finished a cross country flight on Southwest with my child who has a nut allergy. Luckily it is mild enough that all we have to do is decline the peanuts and have no concern about peanut dust from people close by . I will say, however, that unless Southwest changes manufacturers, the real danger is not from the peanuts but the pretzels. Peanuts are obvious but if you read the warnings on the pretzel label you will see that they are manufactured in a facility that also processes tree nuts. This means that the pretzels are also unsafe for those with nut allergies (including my son). I am sure those with severe nut allergies are diligent about reading the labels- so hopefully a non-issue.

With that said and if known by Southwest- this is more of a cost savings than anything else.