FMC vs interlaken

The following Samtec document discussed the high speed characteristics of a cable assembly that mates with the same connector.

http://www.samtec.com/documents/webfiles/testrpt/hsc-report_hdr-153514-xx_vita57-hpc_web.pdf (http://www.samtec.com/documents/webfiles/testrpt/hsc-report_hdr-153514-xx_vita57-hpc_web.pdf)

It discusses the cable's speed rating and suggests 15Gbps should be possible.

So, yes. You should be able to implement a physical layer link, operating an Interlaken protocol, over the FMC connector.