Technically releasing a brand new and improved version of the figure will devalue it more than a straight rerelease, and that doesn't violate any edition sizes. So counting on long-term value is always a dicey area.
However, this does create a potential negative impact on Sideshow's business, especially if it continues. If people start thinking they don't need to buy the figures right away because Sideshow will always rerelease them if they get too expensive on eBay, it could lead to slower and lower sales of new product. MattyCollector moved AWAY from the constant rerelease model years ago and vowed that no MOTUC figure would ever be rereleased in a bid to increase sales.
Sure SS may see some drop in exclusive only type collectors but I don't know if they have a significant impact or not. mattycollector/digital river has a myriad of problems that caused people to stop collecting(I collected MOTUC since SDCC King Greyskull) in addition to MOTU being extremely niche, Star Wars is pretty mainstream.