It depends on what you mean by pretzelling.*
A buckled wheel is out of true because of localised spoke tension or lack thereof (i.e. broken spoke).
A pretzelled wheel collapsed in order to relieve an oversupply of overall spoke tension.
A pretzelled wheel takes on a saddle shape because the rim could not handle the tension. In a 32-spoke wheel it is extremey difficult to get the overall tension so high that the wheel collapses (pretzels) but on a 32-spoke wheel you can do it in the bench whilst building.
If you have a wheel that's just-just on the limit, a small change in tension because of riding will make it collapse.
Point is, for use other than extreme use of sorts and touring is not an extreme use, 32 spoke wheels are just fine. Then again, if there's a free dynamo to be had, the optimum number of spokes is whatever that dynamo has.
*
A wheel of course does not collapse into a pretzel shape. A pretzel being a pastry that's flat, like a wheel. What is meant by a pretzel shape is a saddle shape, or hyperbolic paraboloid. A wheel collapses from its flat disc shape into that shape, in order to relieve tension in spokes and compression in the rim. The wheel doesn't collapse into a perfect hyperbolic paraboloid because the rim is no perfectly uniform. It has weak spots and strong spots, notably where the valve hole is drilled (weak spot) and on the opposite side, at the join, where a lug is inserted into the rim before it is welded. This makes the rim stronger at the join than the rest of the rim. However, one can still recognise the familiar shape even if it is slightly distorted by rim non-uniformity.
