Theravada For The Modern World is another one you could have used.
As for the suggestion, we're always reticent to create new forums unless they are structurally required to facilitate a variety of discussion that could not be done elsewhere.
The fact that in this instance there were multiple sub-forums which could have suitably hosted your topic, suggests to me there is no problem.
I feel that Dhamma Wheel covers the Buddha and the Dhamma parts of the triple gem pretty well but could see some improvement in the Sangha part.
We're certainly not averse to that... but it would be a matter of thinking hard about what the forum would be focused on, and why such conversation cannot be profitably be held in other areas of the forum.