Look, the point of this entire thread is whether Mu has even the POTENTIAL to break or threaten the WR, not whether she actually will do so. There is no point in discussing that if you aren't willing to grant us the working assumption that a new WR would probably only be possible, if at all, under near ideal conditions that would be meticulously arranged for in advance.
Since there really is no other competition currently in that time neighborhood, it's going to be a race that in all likelihood is rabbited by another phenomenal runner or two that could get Mu at least through 500m on pace. It's going to be in a reliably nice weather venue like Monaco (or some similar European locale), Stanford, Los Angeles, etc. And the race will be scheduled--or her training designed--for her to be peaking within a given training period.
So if we want to accurately evaluate the gap between where she is now and the WR* you have to first start with an accurate number (even on paper, it's 4.45 seconds, not 5 seconds) and then you have to evaluate her performances to date in terms of how far they depart from those ideal conditions. And I'm going to argue that a 1:57.73 run in cold conditions into a 16 mph headwind on the backstretch against competition that finished more than 3 seconds behind you departs pretty damn far from those conditions.
Serious question: have you ever run an all-out 800m in sub-50 wind chill with over 15 mph winds in your face for one entire side of the track where you had no competition and no one ahead of you even partially blocking it? Oh, and also while you're in the middle of a long training build-up designed to peak for races 6-10 weeks later? If so, how closely do you think that performance corresponded to your potential 800m fitness?
If you don't think those conditions and the lack of rabbiting/competition are worth at least a second if not closer to 2 seconds, then you really don't know (middle) distance running. I'm going to go with the wisdom of coaches and meet directors everywhere in concluding that good conditions and competition and timing of record attempts matters A LOT.
Now, to be fair, I agree with you that the perfect confluence of conditions for attaining a WR is very rare. And, if I was forced to bet all of my assets today on whether Mu will ACTUALLY break the WR in her career, I guess I would probably bet against it for that reason.
However, and this is a big "however", that is not the point of this discussion. Again, we're debating POTENTIAL, whether there are any set of conditions where her body makes it through 800m of distance in close vicinity to the WR. And I remain of the opinion that a body that at 16 could run 1:23 for 600m (indoors!) has the potential to run a relatively pedestrian (by elite middle distance standards) 30.4 seconds for an additional 200m with sufficient training, development, and under great conditions.
I think all of this will be even more abundantly clear in another month or two once Mu is further along in her NCAA and Olympic build-up assuming the conditions are good for her races. She'll be running in front of a home crowd for both SEC Outdoors and NCAA West Regionals and then at Heyward for NCAA Outdoors and the Olympic Trials. There will be a much faster than 1:57 time run at at least one of those meets. Mark it down.