In improv, "Yes, and..." is kind of just the basics. It's to stop beginners from putting up a brick wall that kills the scene or forces someone to invent a whole new premise from whole cloth. That shit takes work on somebody's part and adds a ton of friction. You're supposed to
add value, and not
destroy value. ("Yes" stands for not-destroying; "and" stands for adding.) That doesn't necessarily mean agreeing all the time; in fact any half-decent dramatic scene had better involve conflict of some kind or it'll be boring. But you're supposed to find ways to do it within the reality of the scene, i.e. without negating the underlying premise.
If the analogy is applicable to business at all, it's about accepting the "reality" of the place you've parachuted into. Part of that might be to start with the assumption that people are grownups who have real honest-to-god reasons for saying things. That level of respect for strangers seems appropriate, and a lost art in these days of the online echo chamber. Then your job stops being about "being right" and more about listening. This whole viewpoint seems to say it's more important to keep the "scene" going than to be right.
Whereas in theatre you have the luxury of just declaring that yes indeed it IS snowing; in business it sounds like it would be more about figuring out why this person thinks it's snowing. After enough time immersed in their company culture you might see why, and you might even reluctantly agree with it. But you can "disagree without negating" by saying for example "Well I know it's probably not snowing in Cancún." In other words "When I worked at Blablacorp they had an excellent anti-snow system." Seems like maybe caution would be in order before saying anything like that though, as an outsider, because the obvious response is gonna be "Well this is YADDATRON, NOT BLABLACORP! At Yaddatron, it's goddamn snowing!!"
Anyway, point is, you don't necessarily have to accept that it is snowing; sometimes just accepting that the person thinks it's snowing is enough to keep things moving along. I dunno, don't mind me, this is new to me (improv isn't, but this way of using it is), so to some degree I'm thinking by writing.