ModelSim ME Pro is a custom edition of ModelSim PE.

Quote: "ModelSim ME Pro is a custom edition of ModelSim PE that is integrated into Libero SoC's design environment. ModelSim for Microchip is an OEM edition of Mentor Graphics ModelSim tools."
For details, please refer to the "Verify Pre-Synthesized Design - RTL Simulation" section of the Libero SoC Design Flow User Guide.

Scroll down the Libero SoC Design Suite page, go to Documentation and open the User Guides tab.
Access the Libero SoC user guides for each version.
https://www.microchip.com/en-us/products/fpgas-and-plds/fpga-and-soc-design-tools/fpga/libero-software-later-versions

Please note that ModelSim ME Pro will be the default simulator for Libero SoC until Libero SoC v2024.1.
Libero SoC Design Suite v2024.1 Release Notes Please refer to "1.3.1 ModelSim Pro ME and QuestaSim ME Simulator Tools Upgraded to v2023.4" in the "Updated 2020" section.