I'm not sure if this is necessarily a "not planned" feature, though I'd say it's quite unlikely. We actually spent a lot of time considering this and there are a bunch of caveats with it, some of which roughly fly in the face of how users normally interact with a forum. Notably, if you're not doing date ordering of threads, you will basically disable thread read marking in those threads, which may prevent people from jumping back into a thread from where the left off. You could compromise and only display this order to guests, though then you are creating a pretty different experience once somebody registers. If you're mixing discussion threads and questions, you'd also create an inconsistent behavior which might catch people off guard.
