Don’t worry about temps unless you are overclocking or forcing it to run at high loads non-stop for weeks, which won’t happen with MSFS nor regular games. In particular MSFS mainly uses higher CPU load during initial flight loading not during regular flying unless you have an unbalanced CPU-GPU combo or impossible crazy graphical settings for your setup.
Nowadays you will be thermally limited quite frequently as CPUs have so many cores and standard cooling solutions can’t perform any better than they do. We are quite close to the physical limitations the current technology has.
CPU have several built-in protections and won’t allow themselves to run hot for more than just 1 second basically. You will most likely change CPU yourself by a newer one before it really shows noticeable degradation in its lifecycle.
Cheers