Before I left Apple ~10y ago, it was pretty common to drop linked-on-or-after hacks into AppKit and UIKit to keep popular software chugging along. Assuming they're still doing that sort of thing, this was either missed or deemed not high-enough priority to add such a check (or maybe one was added, and the only reason this issue has been noticed is because Electron and Electron apps are now being built against the macOS 26 SDK).