Fender is in a tight position as a brand, because their appeal and the value of their brand derives very strongly from their history and legacy, but they need to sell new instruments to make money. Electric guitars don't really wear out and you can't keep the brand alive just selling strings. The vintage / collectible market adds to Fender's brand name cachet, but they don't make anything off it directly, obviously.
If they do anything really new they lose the vintage cachet, but if they just keep churning out the same Standard P and J basses, they aren't taking full advantage of the vintage appeal, since the modern instruments will never have the distinctiveness (and nostalgia appeal) of the fewer-in-number instruments on the vintage market.
The proliferation of reissues, small variations on classics, and signature models (which I agree is a bit overdone and confusing) is their attempt to capitalize on that vintage appeal, introduce pricepoint levels, and have elements of distinctiveness or artificially limited supply (this may be one reason that models come and go). I don't think it's a coincidence that Fender has all of these reissue models now, when even CBS-era vintage instruments have a collector's premium.