To put that aside and address your larger point, then if we had just one candidate that provides "an explanation for BHIP that does not introduce any new assumptions or very small assumptions to existing theory", then it would indeed be a plausible candidate explanation. That is not, however, the situation we are faced with: Hossenfelder's argument is that there are many equally plausible (and equally speculative) ways in which the paradox could be resolved (though none that "[do] not introduce any new assumptions or very small assumptions to existing theory"), with no prospect of us getting the data to choose between them (note that Hossenfelder is highly skeptical of choosing between theories on the basis of 'beauty', 'elegance' or other subjective distinctions. As I explained above, Occam's razor is not in this category.)
As far as I know, this argument might fail if some data from a seemingly unrelated field supports just one of the candidate resolutions of the paradox. This might be the point you are trying to make, but if so, your "gravity might fail" analogy isn't helping, as we are not currently faced with multiple, equally-plausible theories of gravity, one of which will be preferred if gravity stops working in 1000 years (speculating that it might do so is neither an observation nor a theory of gravity, it's just speculation.)
Hossenfelder's counterpoint, disussed on HN in the past:
"A contrarian argues that modern physicists' obsession with beauty has given us wonderful math but bad science
Whether pondering black holes or predicting discoveries at CERN, physicists believe the best theories are beautiful, natural, and elegant, and this standard separates popular theories from disposable ones. This is why, Sabine Hossenfelder argues, we have not seen a major breakthrough in the foundations of physics for more than four decades. The belief in beauty has become so dogmatic that it now conflicts with scientific objectivity: observation has been unable to confirm mindboggling theories, like supersymmetry or grand unification, invented by physicists based on aesthetic criteria. Worse, these "too good to not be true" theories are actually untestable and they have left the field in a cul-de-sac. To escape, physicists must rethink their methods. Only by embracing reality as it is can science discover the truth."
Hossenfelder's blog: http://backreaction.blogspot.com/