Is this kind of question too soft for here?
There are harder and softer phrasings of the questions about publication.
Questions like "is this result original" or "what is the closest result to X in the literature" are ordinary [reference-request].
The question "is this proof potentially publishable", meaning "would it have an appreciable probability of being accepted for publication", is subjective but more or less answerable for specific types of journal. There are so many different journals that a correct and seemingly new theorem or proof can usually be published somewhere, which makes the completely general question of publishability less meaningful. Stating it in terms of whether the result is "interesting enough to publish" would make the question even softer and subject to the objections in the other answer.