The theory of having better conditioned legs is that they would take longer to fatigue thus allowing a bigger gear, more power, to be used for longer. So the question is would riding in a way to quickly overload and stress the legs create enough stress to cause the adaptation desired?
I think the consensus is that it may do, but the adaptions and the outcome would not necessarily be any different than riding at normal cadence in a more appropriate gear. Either way, the same muscle fibres are recruited. So in other words, either would work. So on that basis, it would be logical to apply the rule of specificity and do the thing you would normally do, rather than do something different for the same effect. Coggan addressed this in one of the articles I linked to earlier.
It is also important to stress that the ability to ride in a bigger gear for longer is a function of sustainable power production (FTP, aerobic capacity, cardiovascular capability, Vo2 Max, lactate tolerance, etc, etc), not leg conditioning or leg strength, as I said before.
