I'm more in line with Chardrizard. They should develop it so that the fight/obtainment is really difficult, (R50 group crafting +3's from incredibly difficult unique/untradeable monster drops would be my preferred hypothetical scenario) not just drop rate. Drop rate takes no skill only patience. The downside to that is strategies are shared and eventually, everyone has it in three months, hence Naoki Yoshida's take on it.
The elitists still get the feeling they want by having it before everyone else. I don't think it's necessary to incorporate arbitrary time restrictions on gear or content. Add filters via worthwhile obstacles and game content, but drop rate is pretty lame in my opinion.
When it comes to it lasting three months that entirely depends on what you think "lasting three months" is in reference too.
1.) New/Better gear is implemented so fast that it makes previous gear obsolete.
2.) Everyone figures it out after the elitists post their strats but that gear remains "cream of the crop."
I'm okay with option two. I think FFXI relics were kind of ridiculous, though I'm glad they let you Trials of the Magians them to make them better. I think that's how the materia system will put individuality and long term value into gear, which I'm really excited about.
So Azurymber, to answer your OP, it really depends on what "lasting three months" means, in this case, for me to give a more definitive answer.
When you implement and impossibly low drop rate combined with content that requires 18+ people to complete per run that just creates a pyramid scheme type situation where the people who "get theirs" "get out" never to be seen from again.
I'm more inclined to the "impossibly difficult" content. I'm not a huge fan of timers but I'd even take that over the alternative of needing a massive amount of people and waiting in line for drops.
I think the materia system will address this.