Yes, that's exactly it. Their most advanced weaponry is being made and used instantly, as opposed to being drawn down from older stockpiles. This is suggestive that those initial stockplies are gone, and that they're having to use things as fast as they can make them.

It paints a picture that they are struggling to keep up, that they're not capable of further quick escalation, and that they'd be very sensitive to a disruption in the delivery of components required to make these things when they're using them as fast as they can build them.