My assumption is that Ricoh acts similarly to Nikon in that they only greenlight select few projects and expect them to be profitable quickly. So success and failure of a lens/camera is judged quickly and any longer sales success is just an added bonus.
Probably they have optimized their fixed costs and other manufacturing and inventory costs, so they can live off small volumes.
If the DFA* 50 preorders have sold out I expect it to be considered a commercial success either already or very soon.
That is a good ingredient for them to move on with the next lenses. The 7.5 kg 85mm F1.4 lens.
While this approach is slow, it ensures sustainability even through longer drought periods.
Obviously this is not an option you could choose if you depend on huge marketing budgets and super quick release cycles (Sony, Nikon, Canon).
Sometimes smaller is better.