It sounds like the acquirer needs to be ready to support network-level tokenization. I have no idea how an acquirer can detect what kind of card it is an compute interchange when everything is in the same BIN.
The Tokenisation FAQ by EMVCo suggests that the BINs could be selected from the card network's existing ranges, which would allow merchants and acquirers to simply pass them through to the network (where the de-tokenisation is performed):
http://www.emvco.com/faq.aspx?id=264#13