"So does this mean that the 1TB WD10EACS-00ZJB0 and WD10EACS-00D6B0 drives aren't affected?"
No. It just means WD doesn't offer a solution for these drives. (Solution = firmware update or utility to configure unload delay.) To solve it, you need to tweak your OS and other software to fit your HDD's behavious instead of the other way around.
Both 00ZJB0 and 00D6B0 are definitely affected by "it". I'm still refusing to call it an issue, so it's just "it" instead.
Though, noisewise it may be an actual issue. The clicks during load and unload process are slightly louder than non-AAM seeks and are audible in decently quiet system... in a completely silent system, some silencing fanatics would probably consider them obtrusive. But for reliability, I wouldn't consider "it" a confirmed issue.
For people who are sensitive to seek noise, maybe giving Samsung EcoGreen 5400rpm is a good option? They are (AFAIK) CSS based like their 7200rpm counterparts, and thus they have no power-saving modes, thus no clicking sounds related to them. Though some say the seeks themselves are quite loud on EcoGreens... probably not load as per se, but with idle noise being less than 7200rpm F1, the 5400rpm variant might have more noticeable seeks due to lower noisefloor of the system.
Too bad Hitachi doesn't make 5400rpm drives as they use APM for unload configuration and the aggressiveness of power saving has been customizable since... the first model that actually had the unload technology? But Hitachi has declared that they won't try to "cut corners" in power and noise by reducing rpm to achieve results easy. This means that unless 5400rpm is re-introduced as an industry standard, Hitachi won't follow WD and Samsung. Seagate would probably be more likely to be the next to introduce 5400rpm but I wouldn't bet on it.
"hmm im still confused wether there is a problem or not"
It's wise to be confused because the reality is that we don't know if there is a problem or not. The nature of the potential issue (or "it") is long-term
reliability. GPs have been around for a year and it's service life is 5 years. So, we'll probably have the answer to whether there is a problem or not in the next 4 years.
"and which models are effected"
is: all GreenPowers, RAID and non-RAID, 1st generation (250GB/platter) and 2nd (333GB/pl), flagship capacities and downscales.
WD Black is probably unaffected as it's performance oriented and recovering from unload would cause a 0.5 to 1.0 second delay in requested IO operation.
WD Blue? I don't know, but probably unaffected. This is just a guess as well.