So, to summarize,

Let's call the world without any interference, the "real" world

And about a year ago, Machan-kun encountered a precarious situation

And this, Unidentified Mysterious Animal (UMA) protected her from what you might call her destined fate

But as a result, her existence began fading away from our "real" world

REALITY

DISAPPEARANCE

Truly a tale that's difficult to believe in,

But the individual elements themselves are not without precedent

Supposing that she was supposed to encounter a crisis in our reality,

Perhaps that is related to Machan-kun's inexplicable health problems

And there have been several confirmed cases of umamusume suffering from unexplained illnesses in the past

Most recently, there was the case of Rhein Kraft's coma

Unfortunately, a definitive cure for cases like hers has not been found, but it is reported that many recover.

And, if it was a disease she could beat, there would be no need for "that" thing's protection, wouldn't there?