Yes. It does include a new microphone. Mics in apple devices are nearly always adhered to spome part of the housing, so they often come as part of other assemblies when you replace them via Authorized Service. The top case for this model (to the best of my recollection, I’ve been out of the Apple Authorized repair system for about a year now) includes:
- Keyboard
- Speakers
- Battery
- Touch Bar
- Microphone
Unlike previous models, I don’t believe the trackpad comes in the top case for this model, but I could be mistaken. The microphone lives on the left side of the laptop near the speaker. it has its own little connector on the edge of the logic board.