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Trace the number to its equation
In the original record q=0.5 comes from [100×1.05−80]/[130−80]. No historical observations or survey probabilities enter the calculation. The number reconciles the stated price and financing model.
Keep another probability explicitly separate
A separately supplied actual higher-state probability of 70% would give an undiscounted expected call payoff of 21 rather than the pricing-weighted 15. These are different expectations under different weights.
Do not automatically discount the actual expectation at the risk-free rate
Using 21/1.05=20 does not reproduce the replication value 14.285714. Pricing a risky actual expectation needs its own valuation framework; the actual probability alone does not justify a risk-free discount.
Label the model quantity
Use higher-state pricing weight or risk-neutral probability in this model. Keep forecast or observed probability for data and assumptions supporting that separate interpretation. A common numeric value in a special case would not merge the concepts.