At this late stage of development the financial impetus would be to mitigate losses. They've invested time and money into the port for quite a while now, even if they're expecting poor sales they'll be financially better off releasing the game in the hope that they'll make some money back rather than not releasing it all when the game is almost finished. If they didn't release the game they'd have to swallow the losses completely.
This is Ubisoft - who must have made a profit from ZombiU, Rayman Legends, Assassin's Creed III and Just Dance - not EA who decided to swallow the losses on Crysis 3 purely due to their hissy fit rather than sensible business reasons.
I'm not commenting specifically in the case of WD, but it's not as simple as you say.
It isn't like publishers go, 'okay today I will ship 200,000 copies of Game X to recoup my losses!' - retailers have to actually
order copies of the game. People like to say 'why didn't EA ship more?!' like it's some unilateral decision. They have big sales teams that meet with Walmart and Target and GameStop that actually have to sellin-in orders to these guys. Sometimes, they just don't buy. If Target and WM decide the return isn't there or the title is a risk, they might just be like - naw, all good. i'm only going to carry ps3/4/xbox/one platforms today, here's a 500k day-one order on what I know I can sell.
So, that's a factor. If pubs can sell in enough, they might just not ship, unless someone comes in with financial incentives or they make deals with retailers requring them to carry SKUs in exchange for a guaranteed marketing spend/supprot and things like that.
THis, by the way, is how most of retail works - not just gaming.