And they still haven't reintroduced their 5-string with the pup magnetic field issues. How long can that possibly take? Even Epi only needed a couple of weeks to get the pup issue on the TB Pro 5-stringers right. It seems that Ric is forever stuck with being able to get just one bass right, the 4001/4003.
They have priorities and this isn't one of them.
John Hall answered this way back at DP 2. He said that according to a certain trade magazine, all of the ten best selling basses were 4 stringers. He just wasn't prepared to use his already overloaded resources to make something that doesn't sell well.
IMO it's another case of what you read on bass forums not matching the real world.