Yes, the description from TFA does not match the traditional Thunderbolt networking protocol, whose performance may be as low as that of a 10 Gb/s Ethernet interface.

The description from TFA matches what the poster above you said about a new Linux device driver that allows access to the raw Thunderbolt protocol for transferring data between computers. This appears to be an independent implementation of the same principle as in the device driver that will be merged in the mainline Linux.

While the official Linux device driver makes the raw Thunderbolt appear like a file, which can be written and read to transfer data, this implementation emulates an Infiniband interface, which presumably was simpler to use for distributing work over multiple GPUs.

They actually mention that with traditional Thunderbolt networking on the same computers, they had obtained only 9 Gb/s, i.e. more than 5 times slower than what they obtained with raw Thunderbolt.