Yesterday saw the latest episode in a Prosser versus Gurman battle over just how big a change well see in the look and feel of the user interface in iOS 19.Bloombergs Mark Gurman says hes seen evidence of a change almost as notable as that of iOS 7 back in 2013. Jon Prosser, on the other hand, says we should expect something far less dramatic Prosser versus GurmanGurman reported earlier this month that this year will see a completely new look to each of Apples key operating systems, as well as significant new functionality.Apple Inc. is preparing one of the most dramatic software overhauls in the companys history, aiming to transform the interface of the iPhone, iPad and Mac for a new generation of users.The revamp due later this year will fundamentally change the look of the operating systems [and] is loosely based on the Vision Pros software []The changes [] go well beyond a new design language and aesthetic tweaks. The software will mark the most significant upgrade to the Mac since the Big Sur operating system in 2020. For the iPhone, it will be the biggest revamp since iOS 7 in 2013.Jon Prosser, in contrast, is playing down expectations. While he did show a mockup of a significantly new-looking Camera app back in January, he yesterday shared that he says is a screenshot of the new Messages app which doesnt at all appear to indicate a radically new look. The changes shown are relatively minor tweaks.While most of the interface looks the same, we can see slightly redesigned buttons at the top. The buttons are now covered by a circle with a reflective glass effect, similar to visionOS. The iPhones virtual keyboard also seems to have been slightly redesigned, now with more rounded edges.He went further in a podcast episode with Sam Kohl, A lot of people have very high expectations for what this redesign is and as far as Im aware right now it doesnt meet those very high expectations [] so I hope people are just not you know super disappointed.He specifically addressed Gurmans reporting.Im not going to say that Mark Gurman is wrong [but] from what were seeing its not as substantial as its being made out to be. It is a redesign, some things do work slightly differently, but its not like iOS 7.Gurman hit back, not directly naming Prosser but clearly referencing him.iOS 19 images floating around arent representative of what well see at WWDC. They look to be based on either very old builds or vague descriptionsiOS 19 clues from AppleYesterday also brought us some clues direct from Apple. The company yesterday announced the dates for WWDC 2025, and the frosted glass graphic certainly appears to back the idea of a visionOS-inspired look.Parker Ortolani also suggested that an animation for the event creates high hopes for some super fun new motion design in the next releases.9to5Macs TakeWhile we know little at this stage, my money would be on iOS 19 being more toward the Gurman end of the scale than the Prosser one. Apples graphic absolutely backs the latters reports of a glassy, three-dimensional look.Its been a very long time since weve seen a fresh new UI look from Apple, so its certainly time and as I said previously, a new look will probably have a bigger impact than the long-awaited Siri improvements.Highlighted accessoriesGraphic: And machinesonUnsplashAdd 9to5Mac to your Google News feed. FTC: We use income earning auto affiliate links. More.Youre reading 9to5Mac experts who break news about Apple and its surrounding ecosystem, day after day. Be sure to check out our homepage for all the latest news, and follow 9to5Mac on Twitter, Facebook, and LinkedIn to stay in the loop. Dont know where to start? Check out our exclusive stories, reviews, how-tos, and subscribe to our YouTube channel