We know so little about biology that any kind of research can lead transformative benefits. Therefore the outcomes of a certain line of biological research including GoF are unknown. Penicillin is a great example of this.

> COVID did - not - change the probability.

True from the perspective of omniscient universe, but for humans with limited knowledge, it will change our priors based on the origin.

There is a valid reasoning for how GoF research can lead to pandemic but we do not know how often it will happen in practice. There are many things we already do with potential global consequences. Historical example is the risk of chain reaction during first atomic test. Contemporary example is the universal dependance on digital infrastructure which can be hacked. Timeless example is asteroid hitting the earth.

We make decisions for each of the scenarios based on perceived (objective + subjective) probabilities and the tradeoffs.

If natural origin is proved, there is less reason to add mitigations to the GoF research because mitigations are hard to design and limit the exploration space.

To summarize:

P(GoF causing pandemic) = P(GoF) = GoF pandemics / total pandemics

Mitigations ∝ P(GoF)

If natural origin, P(GoF) stays same. If lab origin P(GoF) increases and calls for commensurate increase in mitigations.