Does the C-19 have an NMRA 8-pin connection point for DCC decoders?
No. It has a 23-pin connector ("standard" for large scale in that both Aristo-Craft and Bachmann use it). QSI, ESU, and Zimo make plug-and-play decoders for this socket. Bachmann includes a plug-in interface board which plugs into this socket with a whole bunch of wires that you would use to connect to any other DCC decoder.
Know that the C-19 draws upwards of 4 amps at full stall, so you're going to want to use a DCC decoder which can handle that much current. None of the DCC boards with the NMRA-standard 8-pin connector can handle that much current anyway, so it's no big deal that Bachmann wouldn't use that 8-pin interface in their larger locos.
Later,
K