In secondary school, I was taught that all laboratory experiments must include an explicit, a priori hypothesis statement with an associated theoretical foundation. For example, one of my lab reports might explicitly state, "I predict that the test tube of xenon will not demonstrate any observable reaction to the heat of the Bunsen burner in the presence of oxygen because xenon is a noble gas and noble gasses do not react except under extreme circumstances." At the end of the paper, we were required to explicitly state whether or not the hypothesis was supported by our findings, e.g. "The results above clearly demonstrate no reaction to applying heat from a Bunsen burner to a test tube of xenon in the presence of oxygen for any of the time intervals in Table A. It has thus been demonstrated that the hypothesis has been shown to be true."
What I've found in the real world is that actual, published studies generally do not include such an explicit hypothesis. The hypothesis may be implicit in the study's formulation or background, but at no point do the researchers actually come out and say, "This is what we think will happen". That is, someone who knows enough about the research field will have a good idea what the hypothesis probably was, but it is not formally stated in the paper. I do see a lot of papers with implicit hypotheses that look something like:
Understanding whether reticulating the splines of wooden spoons produces a GHV value that is positively correlated with the price of rice in China is important to proving the No Free Lunches conjecture [McGillicudy & Jones 2013, Smith 2015, Lopez 2018]. We use the Glover-Branch Method  to apply positive pressure to the negative gradient of our standardized set of wooden spoons to determine the second coefficient....
At no point in this do the authors come out and say, "We think reticulating the splines of wooden spoons produces a GHV value that is positively correlated with the price of rice in China", but rather we perceive it as implicit in the narrative.
When publishing research, when (if ever) is it required to explicitly state an a priori, theoretical hypothesis rather than leaving it implicit?
To be clear, I'm not asking whether it is ok to proceed with research without first identifying a specific hypothesis, but rather whether it is essential to state or disclose the hypothesis to the readers upon publication or whether explicit hypothesis statements are really only a pedagogical tool for students.
In many cases, of course, the hypothesis will be supported by the data and there should be no problem stating so, but I'm thinking about cases where the researchers' hypothesis was found to not be supported. In that case, is it required for the researchers to "admit" that they jumped to a false conclusion in their initial hypothesis or is it sufficient to simply publish the results?