But luckily it automatically readjust itself to earth automatically every half year exactly for these events. So on 15.10 we will know, if it is really lost. In either case, the end of its mission is near anyway, because the nuclear batteries are near its end.
edit: Nasa has a blog post on this https://blogs.nasa.gov/sunspot/2023/07/28/mission-update-voy...
The hardware is the same, but they've updated, patched, and rewritten the software that's running in it throughout the years.
I'm not suggesting that the failsafe mode wasn't originally considered, and implemented, but simply that it doesn't have to be the case. They could have made changes to it over time.