> Is there no possibility that manufacturer defects or a solar anomaly that could cause unexpected problems?
There sure is. At least two of the systems (positioning and water cooling) are active systems that could fail.
> but should we be so confident without actually having done something like this thousands of times?
"we" are confident enough that we rely on it to protect a > 1 billion USD probe. What's the use in adding a lot of ifs and maybes to some piece of marketing/explanation?
If it fails, adding some ifs and maybes to a marketing video won't really change anything.