Richard over in The Kingdom evidently has quite a cache of weaponry set aside, and Daryl now knows about it.
If Daryl tips off Rick that they can just swipe Richard’s stash, we might not actually see any deals struck with Oceanside any time soon.
He doesn’t seem to be overflowing with loyalty to Richard after Richard was so willing to risk Carol’s life, and we can bet that he’d jump at the chance to arm a new group of allies and strike back at the Saviors.
Of course, Rick does have another potential source for guns for Jadis, and it’s not one that would require him to travel all the way to Oceanside.