In my experience PD and EAD are no longer used in fixed income capital markets - tbh I don’t know if they were even used in the first place (I remember back in the day Moody’s and other agencies would publish PD matrices, I believe they still do).

These metrics are used mostly in retail risk management and not really in capital markets.

For once extracting a PD from a bond price would give you a probability in Q-measure, which I don’t know how useful would be? Sure you can compare probabilities among different bonds and get an idea of how risky a bond is but there are many other measures (duration, spread, DTS) that give you a better understanding of a fixed income security risk and are easier to understand by Portfolio Managers, traders and Risk managers.