They are copying Aimpoint... (jk)
In all seriousness releasing a product and being unable to meet demand is nothing new in the gun industry. Just ask the people who had to hunt and pay scalper pricing for S7W magnum revolvers back in the day. COVID and the Ukraine war haven't helped.
Holosun has been making and importing the EPS and the EPS Carry, like a lot of imported products in high demand they are imported in batches and simply sell out faster than Holosun can make or import them. Between worldwide materials sourcing issues, COVID lockdowns still being a thing in China it surprising they have been able to meet demand for existing product as well as they haves.