iPhone 15 Pro button fiasco!
The high-end iPhone 15 models, according to several sources, will include a new unified solid-state volume button with the Taptic Engine to mimic the sensation of a physical click. The volume up and down buttons on the phones could be replaced with solid-state surfaces, according to leaked pictures.
According to 9to5Mac, Tech analyst Jeff Pu said that he had heard from people familiar with Apple's manufacturing chain that the iPhone 15 Pro will probably continue to have physical buttons. This is due to the design being complicated by the need for three additional haptics engines within the iPhone 15 Pro if solid-state buttons were used.

Renowned insider Ming-Chi Kuo confirmed with the news, claiming that unsolved technical problems surfaced before mass production, causing Apple to cancel its intentions to place solid-state buttons on the iPhone 15 Pro and Pro Max/Ultra. Suppliers Cirrus Logic and AAC Technologies, who were supposed to supply the controller IC and the Taptic engine, respectively, are claimed to be badly impacted by the decision.
According to Kuo, the engineering validation and testing, or EVT, phase for the iPhone 15 is currently underway. Since it is the initial validation test, Apple still has time to modify the design. According to Kuo, getting rid of solid-state buttons will also make the testing and development processes simpler. This means that the timing of the iPhone 15 Pro introduction will probably not be affected by these adjustments.
It's unclear if the plan to replace the mute switch on the iPhone 15 Pro with a customisable capacitive action button has also changed, but if the solid state buttons are being cancelled, there's a very slim chance that the mute button will still be coming. Personally, I'm not as concerned about this.

One of the major changes anticipated for this year was the revised buttons.
Other rumoured updates include a new processor A17 bionic for the Pro versions, a curvier edge of the frame, slimmer bezels, a brighter display (2500 nits), a titanium construction for the iPhone 15 pro max model, and USB-C ports with thunderbolt capabilities on the Pro models and USB 2.0 on the iPhone regular models.