Android MでBLE使うにはACCESS_COARSE_LOCATIONが必要だよ

そういうことです．

BluetoothやWi-Fiのような近傍のデバイスをスキャンする系のAPIは使いようによっては位置情報特定できちゃいますもんね．

To provide users with greater data protection, starting in this release, Android removes programmatic access to the device’s local hardware identifier for apps using the Wi-Fi and Bluetooth APIs. The WifiInfo.getMacAddress() and the BluetoothAdapter.getAddress() methods now return a constant value of 02:00:00:00:00:00.

To access the hardware identifiers of nearby external devices via Bluetooth and Wi-Fi scans, your app must now have the ACCESS_FINE_LOCATION or ACCESS_COARSE_LOCATION permissions:

• WifiManager.getScanResults()
• BluetoothDevice.ACTION_FOUND
• BluetoothLeScanner.startScan()

Access to Hardware Identifier- Android 6.0 Changes | Android Developers

ということで，Android M（API Level 23）以降はACCESS_COARSE_LOCATIONかACCESS_FINE_LOCATIONのpermissionが必要です．