The GCF approval reveals that the HTC One Max will support SIM lock although that doesn't mean it will be SIM locked in all of the markets it is sold in. The unit will be stuffed with quadband GSM/GPRS/EDGE giving support to triband UMTS/HSDPA/HSUPA at 900MHz, 1900MHz and 2100 MHz. In addition, the phablet will offer connectivity to triband LTE at 800MHz, 1800MHz and 2600 MHz. Those are also known as LTE bands 3, 7 and 20.
Now that the GCF approval has been made, the unveiling of the HTC One Max shouldn't be too far away.
source: GCF via theUnwired