Venus presents same face toward Earth at closest approach. What do you make of that? Is reference 6 in this Wikipedia article "dubious" and this passage in need of excising or clarifying?


  Venus's 583.92-day interval between successive close approaches to Earth is equal to 5.001444 Venusian [sic] solar days, making approximately the same face visible from Earth at each close approach. Whether this relationship arose by chance or is the result of some kind of tidal locking with Earth is unknown.


Gold T., Soter S. (1969), Atmospheric tides and the resonant rotation of Venus, Icarus, v. 11, p 356-366

Is it still an "unknown" or "crazy idea that didn't develop with further investigation"?

The idea that Venus is tidally locked with Earth sounds far-fetched. We understand the slowing of Earth's rotation, and I don't recall ever reading of Venus's resistance to the change!
I wouldn't call the reference dubious so much as very much out-of-date. The paper in question was written in 1969, which was still pretty early in our understanding of the dynamics of the Solar System, including Venus. There would have been a lot of uncertainty in many of the measurements, such as rotation speed, which would have been determined by radar. Consequently, the possibility of resonance was there, at least until better measurements were available. However, the wikipedia article on Venus, and the attendant 1979 paper citation (#90) indicate the idea of a resonant Venus was rejected decades ago once sufficiently accurate radar observations of the planet had been made. 

So, clarifying of the wikipedia article you mention is probably in order.