They only needed to test with the latest Electron at the time of release (or indeed, any chance version - they're all affected - but latest is a reasonable baseline). If they had, they would've seen this.
There are patches out now, but only after Apple released the OS to the entire team world and people reported the issue to the Electron team.
Imo, Electron is sufficiently popular that somebody should test at least one Electron app on a major new OS version sometime before releasing it as done! Any app would've worked, and there's plenty of popular ones, as this post shows.
There's just no way for Apple to maintain and run comprehensive test suites for all the different software platforms out there, even "popular" ones.
That's why they release betas early -- that gives each project an opportunity to run their own test suites, however comprehensive they may be.
It's a little hard to hold Apple responsible when there are a lot of app teams in a better position to catch this than Apple, and apparently none of them did.
(Maybe it was a late change in Tahoe? Still, no one found it in the RC either it seems.)
No, this is possible, but again, just drain the bathwater of "all, everything, comprehensive 100%" while blocking the baby of glaringly obvious system-wide visible bugs any good 9x% testing would've caught.
There are patches out now, but only after Apple released the OS to the entire team world and people reported the issue to the Electron team.
Imo, Electron is sufficiently popular that somebody should test at least one Electron app on a major new OS version sometime before releasing it as done! Any app would've worked, and there's plenty of popular ones, as this post shows.