That's complete rubbish. As long as the two are connected to your network (the TiVo via Ethernet, the V6 by Ethernet, powerline, or wifi), then you should be able to watch recordings from one box on the other.
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Assuming you retain and pay for the TiVo and it is connected to both the co-ax and your home network via powerline or direct Ethernet cable, you can watch all of your TiVo recordings on the TV connected to the V6.