This post continues previous posts on this topic, such as here.
Once a theory becomes established, it is always valid. It is never falsified. What happens is that its limits are discovered. Any pretense to being universal breaks down.
All theories are limited. Theories are analogies, and all analogies have limits. It is the scientific fashion to initially present a theory as universal, but this is a manner of speaking, not to be taken literally. No theory is universal because all theories have their limits.
When the limits of a theory are known, it is what Werner Heisenberg called a closed theory. An open theory is one whose limits are not known. It may be considered universal, even though it is not. But until its limits are known, no one knows its limits so it’s as if there are none. Eventually, limits will be found.
This means for example, there are several valid theories of the figure of the earth: the flat earth, the spherical earth, and the ellipsoidal earth. Each is valid within a certain domain of accuracy and precision.
There are several valid theories of the celestial bodies: simple geocentrism, Ptolemaic geocentrism, Copernican heliocentrism, Tychonic geoheliocentrism, Keplerian heliocentrism, Newtonian barycentrism, and Einsteinian cosmology. They are all valid within their domain of applicability.
Several theories of biological diversity are valid: fixed species, fixed kinds with limited change, and change over time (evolution). None of these are universal. They all have their limits.