Having development and production be different is generally a very bad idea.
Sure, you can tell your developers to be aware, and they may even mostly will be. But sooner or later you'll run into an issue and your only recourse will be to debug it in production, because development won't have the same problem.
Just because its the same major version of mysql/php, doesn't mean there can't be problems which will only reveal themselves on a single platform.
Now, if you have dev being what ever they want, then a test IIS server, then a production IIS server, you can avoid almost all of these problems.
I can't think of a compelling reason (saving a couple thousand on licensing costs for a test server isn't compelling; my troubleshooting time isn't free) to do this.