If you are saying preppers want to influence others to expect societal collapse, a look at prepper threads and prepper websites indicate they are centered around preppers talking to preppers. If non-preppers post, then they would talk to them.
I have family members who do not prep at all and that is their choice so I don't bring it up.
I don't know of an agenda to bring prepping to the attention of every person in the country - oh, yes I do. FEMA encourages everyone to prepare for an emergency and has a lot of information on their website as to how to do that, so I suppose that would be “an agenda to influence widespread expectation of societal collapse”. They cover a number of emergencies and some of those might bring about “societal collapse” for a time.
Here’s a simple way to analyze this.
1. Who wants societal collapse? Answer: the Marxists.
2. What is a good way to set the stage so that societal collapse can be perpetrated? Answer: get people to think it’s supposed to happen.