If I recall correctly they were also impacted by the lack of hydroboost boosters at the time. BUT they were at least upfront about it. End of the day for me, fabicated my own bracket, hoses, etc. Hydroboost was SO worth it for me and the 14" 6 piston baer brakes at all 4 corners on my dart.
I've been hearing this bull for years. I think Bosch needs a min qty order to ship units. I'm suspect these companies wait until they have enough orders/$ first. There's simply no way it takes 6 months to add a mounting plate and ship a unit.