This product is intended for use in the qualitative determination of pH, as compared to a universal color card. The material has not been qualified for use as an indicator in a solid culture medium. Factors such as medium turbidity may impact the performance. It would be up to the end user to determine suitability.
A brief review of the literature indicates phenolphthalein is commonly used in this application and is generally suitable for autoclaving. Please see the link below to a publication that may be of interest:
https://biokimicroki.com/ph-indicator-used-in-microbial-media/#:~:text=For%20example%2C%20the%20very%20well,indicators%20are%20used%20in%20Microbiology.
Please see the following link to review the product datasheet:
https://www.sigmaaldrich.com/deepweb/assets/sigmaaldrich/product/documents/203/711/109175ug-ms.pdf