No. Concurrent execution allows you to model the behavior of running the model on multiple cores and generate code for it. It is designed for benefit on an embedded application, but it has no impact on the speed of the simulation.
Therefore, when you run the model in Simulink, it still runs as a single-thread application and does not use multiple cores.
Concurrent Execution does however potentially impact simulation results by introducing buffers/delays/dependencies between different components and rate groups.
