I believe that the NRA rules say that f-class targets are to have f-class centers.
Yes, that is the current NRA rule (more or less) for NRA-sanctioned F-Class events. But a lot of events, even prominent events like the Sierra Cup are not NRA-sanctioned. It's a free market. NRA doesn't own a trademark on "F-Class." I appreciate the broad availability of F-Class tournaments that are not F-Class sanctioned.
Depending on where you live and how far you are willing to drive, you have a lot more tournament options if you are not religious about NRA sanctioning. For my buddies and I, having the electronic targets work properly is much more important than visible rings as a sighting crutch. Having more tourneys within a reasonable drive is also more important than the NRA blessing.
In fact, I think we'd list a lot of things as more important for F-Class tourneys than NRA approval: driving distance, scheduling, smooth operation, working bathrooms, F-TR and F-Open separated, recognition of women and juniors, availability in the slower months (Dec - Mar), a covered firing line, timely awards, reliable posting of results, and general friendliness.
The organizers of the Bama tourneys have done an excellent job, but the bad attitudes of the range staff themselves (eye rolling at suggestions of eTarget problems), and the eTarget problems are the big issue.
This will definitely force a change in the types of reticules used by F-class shooters. Many of us are aiming at the X in the center of the target, if it's clear enough to see it. I can invision scopes with coaxial circles in the reticule sometime in the future.
Hey, it's a free market. Most of the ranges in the southeast are still using paper targets with scoring rings, and will likely continue to for some time. They are friendly and welcoming if you are willing to make the drive. My buddies and I didn't really find the big black dot (no scoring rings) to be a significant disadvantage, and we don't expect to change scopes or reticles even if we end up shooting regularly at Talladega.
If they can work out the eTarget issues and bad CMP staff attitudes, Talladega will be a great venue for F-Class events and likely have as many participants as they want without providing visible scoring rings.