No offense, but this shows a remarkable lack of understanding of how companies like this operate. It is incredibly financially bad for companies to have figures, at this price point, sitting in warehouses, unsold for years.
I can almost guarantee you that Hot Toys could care less about aftermarket ebay sales of their figures. If they reissue a figure it is most likely for a number of practical reasons:
1. The initial figure required a number of unique molds and Hot Toys didn't fully recoup the cost of the initial die production and wants to get more out of it. (Hulkbuster or almost any Iron Man figure for example.)
2. Maintaining a specific license requires them to (either from a cost or legal necessity) to produce a minimum amount of products within a period of time. For example, if they don't release a product by the end of a financial quarter, they lose the license or have to pay to re-up it. So maybe their original Arkham license was for five years, and it would automatically continue, at it's current rate, every year after that, so long as Hot Toys released a figure from that license. If not, the license would expire and Hot Toys would have to renegotiate it. This scenario could (hypothetically) see the Arkham license expiring in at the end of the first financial quarter of 2020. But there have been production issues that needed to be worked out with their Batgirl, and she won't be up for pre-order until after that date, or maybe the final ship date is the legal "sales" date, in which case that puts her into 2021. So, now, in order to maintain the current license, Hot Toys dusts off the Arkham Knight Batman, gives him a slight modification and releases him before the end of the financial quarter, thus automatically extending the license for another year in order to cover the release of Batgirl.
3. They feel they need a companion piece to build up or capitalize on sales of a figure that they are worried might not sell well, or have a such a high production cost that they are concerned about breaking even on. They release this new Bats to help promote the new Batgirl, because they worry that some people might only want a Batgirl from a series that doesn't have a lot of figures, if they have a companion Batman for her. Similar to when they reissued the Mark 43 when the HulkBuster came out.
4. There is a sudden and unexpected hole in their release schedule. Hot Toys most certainly has the next few years of figure release mapped out. But what happens when there is an unexpected delay with a figure? Their production schedule may not allow them to simply move another figure up to take its place. But they have been counting on that revenue for the quarter to maintain their current production and development rate. What do they do? They take a previous figure and reissue it, because they can quickly slot it into their production schedule and get it out and not take the financial hit.
