Part of that selection is that the pairs are twisted at different pitches, so that coupling over a long length averages to zero. But if you're only using one pair, as in a DSL connection, and you coil it, coil #1 can couple to coil #2 because the twist pitch is the same. DSL and ADSL etc. are good at making sense of the signals, but not perfect.
The coupling of SIMILAR twisted pairs, if they are adjacent, is not minimal.