Not necessarily, as we don't know how many sales it takes before they cross over into profit. We also don't know how many pieces they have already sold up until now. So without those two key pieces of information it's impossible for any of us to tell how well this release is doing in accordance to their overall plans and expectations. They don't sell as well as the current series stuff, sure, but that's not exactly a surprise to anyone, and that also doesn't mean they still don't make a nice profit at the end of the day, it just might not be as nice a profit as they can get out of the new series stuff. Plus it makes sense to spread out the load a little as far as releases go, so as not to overwhelm the 'new series only' buyers with too much in too short a space of time.
Now I'm sure they'd love to sell out of their releases really quickly, any business would, but I think we tend to forget that 500 is still a rather sizeable run for a niche 'limited edition' high end collectible, and that most things, even amongst the big licenses from the big name suppliers, take their time to completely sell through. So right now I'm not worried, unless Big Chief makes an announcement to the contrary about classic Doctors being no longer viable. But I hope we're still a good way off from the danger of that happening.
That said, I wouldn't be surprised if prices of classic Doctors continued to price creep, nor if the edition size dropped a little lower on the next one (just as I imagine they could get away with making significantly smaller runs and still have them be profitable, if they needed to). In fact I'd say that the edition size of the next classic Doctor will probably be our best indication on how they are going, as far as classic Doctor sales go. Plus, if they believe they can sell Sherlock second stringers like Mycroft and Moriarty and make enough of a profit doing so, then I've got to think that they can do likewise for the classic Doctors, even if the runs do shrink until they find their optimum sweet spot for successfully doing so. And things like the planned Sherlock releases, the TARDIS and Weeping Angels, the prints, extra heads, and so on seem to indicate that they must be doing pretty well so far, in order to afford to have this many irons in the fire. Or so one hopes.
So yeah, even though I'd love to see Hartnell sell out sooner rather than later (just as I'm sure Big Chief themselves would) I'm not panicking personally. Not yet, anyhow.