Not that being hypocritical is always bad but in this case there's zero introspection.
However, it does seem like this is a thing, in particular there was a Swedish study in 2009 that was referenced several times in media coverage and I can find no follow-up or rebuttal to:
https://www.sciencedaily.com/releases/2009/01/090114200003.h...
And then in 2014, an industry-focused article on how to mitigate some of these effects, in particular rodents:
https://www.thepoultrysite.com/articles/range-management-for...
We may be on the cusp of a massive crisis.
Free ranging birds are in less proximity and healthier conditions. There is less contact between them, more sanitary conditions, and healthier birds. But yes, they could have more contact with outside pathogens.
Whereas many poultry barns have thousands of chickens standing in their own excrement, shoulder to shoulder. There are even decaying corpses strewn about and being pecked. Whatever pathogens in there with them could spread and mutate readily, and the birds are likely less healthy and more vulnerable to it.
I'm not sure if there is solid evidence to claim one is more risky than the other, but I think it would be the former.