Setting prices is complicated. I do it for a living, and I don't always understand what I am doing from time to time. But let me give this a try.
In nearly case the the vendor is trying to influence buyers decisions. The newer chip is cheaper, hence you will buy it.
(Oh, and it is better, so what the heck it is a good deal.)
In many cases the vendor may not actually have the older chip in stock, but they don't want to drop the chip from their offerings because they want to look like they have this huge product offering of 100's of different chips, when in fact they are only selling 6-10 chips and only stock those 6-10 chips.
If the prices on those older chips were lowered, a demand for the product could be created, and remember, the vendor does not have any inventory of those older chips, so they really don't want a demand to be created.
This problem of false inventory is quite common with dedicated online companies as their is no chance for a customer to perform an eyeball audit of their inventory and display shelves as could happen to a B&M store.
So what is Newegg doing? Good guestion. But look at this situation from my perspective? Does Newegg really have the older chip in stock? Are they trying to steer customers to a newer, better product?
By the way, I don't sell consumer electronics. But I do have a B&M that sells online. I don't want a customer showing up at my showroom looking for a product that I don't have in my warehouse. So in my business we drop the out of stock or older item from our website. But my dedicated online competitors will leave old, out of date, discontinued products on their websites, often for years, just to boost their product "offerings". It happens in my industry, and I suspect it happens in other industries as well.