A direct classification of components with a category classification in accordance with EN ISO 954-1 into "well-tried components" in accordance with EN ISO 13849-1 does not exist. However, it is safe to assume that in safety terms these components can even be regarded as better than "well-tried", as Category 3 offers higher protection against likely errors than Category 1.
Conclusion: The assumption that it is a "well-tried component" is entirely justified. However, without more in-depth information from the manufacturer on the basis for the Category 3 specification, a maximum of 10 years may be assumed as MTTFd.