Motorola, like Galaxy Note 4 and Note Edge, is in a hurry of getting Android 5.0.1 update. For this, it has treated Moto G first and second generation with latest Android 5.0.1 update.
Some of the users have also started receiving the update earlier but the roll out seems to begin recently. You might not get the update immediately as it can take few days.
We know that Android 5.0.1 updates have been recently released with mostly bugs in it and no specific additions. It seems that the budget phone will provide a great luxury to its users by running this update.