Demanding scientific evidence to support a universally accepted fact is generally not a fallacy, as scientific evidence is a reliable and rigorous means of establishing and confirming facts. However, if a fact is already universally accepted, it may be unnecessary to provide scientific evidence every time it is discussed or mentioned.
In some cases, asking for scientific evidence for a universally accepted fact could be seen as a way to shift the burden of proof. The burden of proof typically falls on those making a claim or presenting a novel or controversial idea, rather than on those discussing well-established facts. If someone is demanding scientific evidence for a widely accepted fact without providing any reasonable grounds to doubt it, it may be considered a weak or disingenuous attempt to shift the burden of proof.
That said, it's important to note that even universally accepted facts can benefit from scientific evidence. Scientific evidence not only supports the initial establishment of facts but also contributes to ongoing refinement and deeper understanding. Scientific inquiry is essential for uncovering new information, challenging existing beliefs, and further advancing knowledge. So while demanding scientific evidence for universally accepted facts may not be necessary in everyday discussions, it remains a valuable practice within the scientific community.