Whether you care about the order or not depends on the intent of the programmer. I think the intent is usually to sum up the array for this sort of code. So, at first glance your first example looks more like a result of something like 0 +- 1e35 in double to me (added one to the exponent to avoid having to do math).
The intent of the programmer always has to be interpreted by the language. I’m saying the default interpretation should be one that doesn’t impose an ordering unless specifically requested. This is much more sympathetic to modern deeply parallel machines.
Very often there's no particular intent, other than to be consistent. You haven't lived until you've traced discrepancies in an ML model deployed across a bunch of platforms back to which SIMD instructions each happens to support (usually squirreled away in some dependency).
The intent of the programmer always has to be interpreted by the language. I’m saying the default interpretation should be one that doesn’t impose an ordering unless specifically requested. This is much more sympathetic to modern deeply parallel machines.