Technically true, which is probably the best kind of true, but if we're going to get technical I did say
closest. You could program a Transputer to use its links as inputs and outputs in a fabric where the implementation details of program counters and firmware running on a particular Transputer were hidden from sight. This allowed for all kind of interesting architectures to be created 'ad hoc' without having to go through the stages of circuit design and so on, and it allowed for much more complex operations than you'd be able to get out of a 'real' dataflow processor on a single tick or message passed from one processor to another because of the much higher level at which they operated.
So sure, they weren't true dataflow processors right off the bat but you could make them look like a pretty good simulation of one on the outside, even if you didn't have access to a crossbar switch (which would be cheating) and absent the real thing that was as close as I was going to get at the time.