Your OS is not nuked, once a proper diagnosis is made, the solution is pretty simple.
If reliability is of the utmost importance to you then maybe a rolling distro is not your best option. Do you need the latest software, system packages, kernels and drivers for your work system? As far as rolling distros go Manjaro is able as stable as it gets. Does this guarantee issues will not arise during updates? No.
On the bright side, if you do experience any issues then Manjaro's community is arguably better than other distros in helping you solve your issue in a friendly and timely manner.
This was a particularly tricky update, and a lot of work and testing was done in unstable and testing repos to minimize issues when applied in stable. Given the scope of what was changed, I am surprised there were not more issues.
Given your system is a work system I would recommend backing up before every update, just in case, Clonezilla is my tool of choice here.
Also, if you are not sure about an update wait a couple of days and read the announcement thread where any issues experienced will be raised and you can follow solutions and / or ways to mitigate any potential issues.