As my profile says, I always advocate for taking the safest approach. Personally, I would only reachedule USCIS interview in one of the following cases:
- Wife giving birth
- Attending funeral of a close relative
- Serious illness
- $100000 cash is given on a spot if I attend some event and skip USCIS interview
I ask myself, what's the probability of USCIS denying petition due to no show if I attend on time with letter? It's probably under 1%, but even that happens in rare cases. What's the probability of USCIS messing up reschedule request? Definitely lower than 10%, but I'd say could be few percent. Would I want to deal with USCIS error? No. So I'd shift any meeting / trip / event to show up to the interview. But that's me.