It wouldn't be month before a strategy were discovered, I would say a week or so. Most of the new dungeons had people beating the bosses after only a few tries. This would make content last longer as well. Maybe instead also of only 1 attempt per day there could be a limited numbers of attempts and a limited number of wins.
The current system already affects the fun for a lot of people as it is. I know some very skilled players that are unable to grind out hours of dungeons per night due to having to take care of their children or work or school. Being able to only do a few runs a night and having it be likely that you will not get a drop is very discouraging for a lot. The current system of playing your luck on drops is pretty awful in my opinion. Yes, I know Darklight gear is supposed to be the "Oh wow look at that gear that guy is wearing!" gear, but people have been complaining about the grind of primals since their release. The fact that SE continued this grind is pretty absurd.
By restricting the number of runs a group can do this will make content last longer which will in turn make it so the content will start to stack up over the time it takes for patches to come out providing a reasonable schedule of events a well organized linkshell can do in a night. I hope SE fixes current content by implementing this or adding future content with similar aspects to this. Personally, my favorite content is the content where one has to complete instances as a prerequisite for higher tiered instances. Much like limbus in FFXI.