The key change in ZBrush 2025 concerns not the main software itself, but what is included in its subscription. A subscription to the desktop version of ZBrush now also includes ZBrush for iPad, a new version of the software for tablets, which was also released today. In ZBrush 2025.0, the GoZ bridge system for transferring data between ZBrush and other software has been updated to support ZBrush for iPad. According to the release notes, to transfer files, you need to log into the Maxon app, and “real-time updates may work differently than GoZ for desktop apps.” The subscription is now the only way to access new versions of ZBrush, as Maxon discontinued perpetual licenses with the release of ZBrush 2024.0 in November last year.
Let me know if you need further assistance!

ZBrush 2025.0 also expands the software's export capabilities by adding USDZ support to the USD format plugin and MOV export to the macOS edition. OBJ export is now also “significantly faster for larger files.”
Additionally, ZBrush 2025.0 seems to be largely a bug-fix update: the only other new features listed in the release notes are new MatCap materials simulating real Monster Clay.
ZBrush 2025.0 is compatible with Windows 10 and later, and macOS 11.5 and later. The software is available by subscription only. The ZBrush subscription now costs $49 per month or $399 per year.
Let me know if you need further details!