Thank you for your comment!

While it is true that the academic world has a lot of evidence behind their studies, this razor would be in better use for theorists and those who analyse the studies, not necessarily those who make the studies.

On the paradox, you are correct that we should not simply accept the new study. The razor should apply to them as well. Whatever theory or assertion, it should be able to explain more than any other theory or assertion to be considered more true. In this case, the new theory provided contrary evidence that the old theory could not explain away. Due to the new theory accurately explaining more than the old theory, the old theory should be done away. In an ideal world, a purely true theory would be able to explain everything and can answer all contrary evidence, but such a theory of everything everywhere does not exist for the universe around us.

I also would like to point out that it is unlikely for one study to completely dispel a decades-old theory like in the example given. In real life, it would take numerous years and many studies and assertions to overthrow a previous theory. I just simplify it for the sake of argument to show the importance of considering if there could be possible contrary evidence and how the razor could fix that problem.

Thank you and feel free to ask any questions.

Edit: Also, it is true that many theorists are very careful about their theories. That would just mean that they use the razor without having a name to it. I am only formalising a razor that people may already use to come up with their ideas.