This is a big deal, not only for the farmers using machinery from manufacturers like Deere, but for the rest of society who may now have some precedent for right to repair.
This doesn't establish any precedent - it's not a law or regulation, just an expression of the opinion of an association of farmers. In the equipment market, they're effectively a consumers' rights organization (except B2B? analogies to the consumer electronics market are inaccurate). Equivalent maybe to large corporate purchasers or a Chamber of Commerce endorsing R2R.
(And also, as the article notes, the national Farm Bureau that the Nebraska group belongs to has already endorsed R2R!)
Perhaps not legal precedent, but many people may feel more comfortable pushing for right to repair if they see "down to earth" farmers calling for it. The ideal is much closer to entering the mainstream now that people other than technophiles are calling for change.
(And also, as the article notes, the national Farm Bureau that the Nebraska group belongs to has already endorsed R2R!)