So then, an unobserved, unreplicated, proposed phenomenon, based upon an unknown environment and unknown operational features must de facto be declared non existent. No evidence is evidence of non existence, correct ?
If you have a hypothesis that positively predicts a phenomenon should definitely be observed under given conditions, and it is not found under those conditions, then that is strong evidence the hypothesis is wrong, cf. Michelson Morley.
If you have a hypothesis that says such and such should exist but does not predict the conditions under which it should be found, and it has not been found, that is weaker evidence against the hypothesis, or possibly not evidence against it at all. As with magnetic monopoles.
Your scenario appears to be the latter.
A scenario like the one you describe, however, might well be set aside as having no utility, per Ockham's Razor. So it could be dismissed from scientific consideration on those grounds, rather than on the lack of evidence for it.