Wingnuts don't need to sell them. They are busy with all their fantastic, surprise aeroplane model kits. They are a small company, not profit driven, and may not have the resources available to push on with the figures without impacting the model kit schedule. Their mistake is to have placed them on the website.
My skills are nowhere near good enough for figure painting, so I'm quite happy for WNW to push on with a BE2, Camel, etc and get around to figures after every WWI type has been modelled!