TLDR: No, not its not.
HOMA is great, but not good enough to justify a wholesale ripout of TCP in the "datacentre"
Sure a lot of traffic is message oriented, but TCP is just a medium to transport those messages. Moreover its trivial to do external requests with TCP because its supported. There is not a need to have HOMA terminators at the edge of each datacentre to make sure that external RPC can be done.
The author assumes that the main bottleneck to performance is TCP in a datacentre. Thats just not the case, in my datacentre, the main bottleneck is that 100gigs point to point isnt enough.