History questions are welcome on this site whenever they have any bearing on our modern understanding of physics. However, if a question has only minimal or null bearing on our current understanding, or it specifically requires a historian's skills, toolset, and mindset to answer, then it should be migrated to the History of Science and Maths Stack Exchange site.
I think we should stay open to a significant set of history questions, and we should keep the history tag. Unlike mathematics, the historical perspective is very often one of the key ways to understand the world and our knowledge about physics. The way physics is structured is very often centered around key experiments, and these are generally thought of as historical events and their contribution and motivation is understood in a historical perspective.
It doesn't have to be that way: you can perfectly well motivate, say, special relativity as one of only two possible cases, with the Galilean case ruled out through muon lifetime measurements, but you don't - you usually start with the Michelson-Morley experiment and tell the story from there.
(Math, on the other hand, does not have to do this: you can simply start with whatever axioms and definitions you want to work with, and you build your theory. Later on, or as an aside or a brief introduction, you might comment, as motivation, that the axioms went through this and then that version before people found the Right Version to use, but the brunt of the work in multiple fields $-$ particularly those taught in depth in physics degrees $-$ tends to follow from the axioms to the consequences rather than the historical refinements of the axioms.)
Going through recent, good-score questions on the history tag yields plenty of questions that are definitely of a historical character and yet have direct bearing on our understanding of physics, and which I think should definitely be on topic here. Taking a few non-rigorous picks,
On the other hand, there are questions that should be moved to the history site, because they require a historian's skills, toolset, and mindset to answer, and because they have minimal or null bearing on our modern understanding of physics. From the first page of the search above, for example, this could include
(For full clarity, these questions weren't migrated because it was too late to migrate them when this question was posted. If they were posted now, they would be migrated.)
However, I find that the set of questions that satisfy that criterion strictly is really rather small. There is, though, a relatively large gray area of questions that are primarily of historical interest, but that still illuminate aspects of how we think about physics and why we no longer think or do certain things. Some examples from this category are
I think these questions should be allowed here: they could also be asked at HSM if the OP is interested in a science historian's perspective, but there is no need to migrate them if asked here, in which case the focus should be (because it can be) on how that part of the historical record helps explain how we think of physics. If the OP wants to shift the focus specifically to what some historical character thought and did, what information they had available, and so on, then it can move to HSM.