My Mom asked her District Manager about pins for "refreshing" lanyards, and her DM didn't have a clue what the point of that would even be, so I wouldn't hold out much luck for different pins. The only way those are going to get there are by other guests leaving them there after trades.
I think the hope is that if they start with the Week 1 pins, other guests who missed out on those will trade for those pins, and then someone who has the Week 1 pins will find something they want, and the guests will keep the lanyards "fresh."
The problem though, is that any new trader probably only has other 100 years of Dreams pins, which makes the lanyards seem boring to the "expert." But that doesn't mean that it will be boring for the newbies. It is going to take time for the newbies to have trading stock equal to what we're used to seeing in the parks.
And it may take some work on our part to get other people interested. Like maybe going to cheappins and buying some of the WDW resort pins to use to trade for the 100 years of Dreams pins so that the "newbies" can see that there are more pins out there than just the 100 years sets. It may mean a few months of experts trading for a pin they already have to make the hobby fun for the newbie, so that in a few weeks they are comfortable getting on ebay and aquiring harder to find pins, or buying from a website that has park pins etc.