I bet they'd be more popular than they think. They'd also have to be fully convinced of that though, since tooling up to make a new flare is expensive enough these days that they don't take lightly to it if it can be avoided.
From my memory of it, tooling up a new product takes from about $14k to over $40k and they'd have to be convinced that they'd make that back and show a profit at some point.
A hard sell with a vehicle that hasn't been made in 37 years. Even though they could minimize initial costs by using the info they have for their existing flares and just make a new profile. Easier than a new vehicle, but generally less profitable too.
With modern R&D computer equipment these days, maybe that price has come down somewhat? At least after the bazillion dollar equipment is paid off? Always some good excuse not to... %)
It took them literally years to decide to offer the second type of rear flare (larger opening) so that EB owners could retrofit to fenders that had already been cut for the larger brands back in the day.
And that was even though EB flares would often pop into the top-ten sales numbers list for sales volume.
I used to get the impression they didn't really believe their own numbers!
Paul