It is a fallacy that your reasoning assumes Forsaken WILL ALWAYS BE EXCLUSIVELY visually represented as Human. It is a fallacy that you claim races have a FIXED visual identity.
Context, you must remember context of your own argument.
The core problem you are using reasoning and evidence that reaches beyond your subjective opinion that they should stay represented as Humans. One example of your reasoning is that they have always been represented by Forsaken Human, implying they should always be. While this does support your argument, that reasoning also implies it can not be changed and that is simply wrong. It is wrong in context of how Blizzard has relaxed their rules on visual identity AND racial diversity (within a playable race) without stating it publicly. It is wrong in the face of Blizzard diversifying the visual identity of races, such as adding fat and thin humans or trolls that aren't all using the same body type. This absolutely applies to the Forsaken, who are uniquely referred to as a collective and not to any specific race. This is also important to note that the starting zone is now Exiles Reach, and that there are no longer going to be unique starting zones with lore limitations behind them. Sand Trolls can be added as customization because the Troll race is no longer exclusive to being Darkspear Tribesmen.
What you don't understand is we are addressing the reasons you are using, not making a statement ourselves that Blizzard SHOULD open up visual diversity within a race. This is not an attack on your beliefs, it is literally criticizing your understanding of what visual identity really means in WoW today. The context of keeping exclusive visual identity is absolutely meaningless today, by Blizzard's own standards. This is what we are pointing out to you.
The issue is not your belief, the issue is specifically your reasoning is outdated and irrelevant to the changes that Blizzard are making today. The Forsaken have never been exclusive to Humans, the Forsaken are not singularly visually represented by any race (considering we have plenty of non-Human Forsaken NPCS), the Player race Forsaken has customization options that break their silhouettes (Bones, no bones, possible hunch removal in the future). Even the lore states openly that the Forsaken are comprised of a number of different races collectively, which is very unique to them and not to any other playable race in the game. Pointing all of this out is NOT an attack on your beliefs.
Its like if someone said all Orcs shouldn't have straight backs, then that is a belief one can have. However if they say only Thrall can have a straight back because he was raised by humans while other Orcs were not, then that is not a good reason because it doesn't limit or exclude other Orcs from having straight back options. Nothing is wrong with having the opinion to keep Orcs with hunches, but everything is wrong with assuming Thrall can be the only Orc with a straight back because of his unique upbringing. If I point out the fallacy of the reasoning, I am not arguing against the belief that Orcs should keep their hunch exclusively. The point is that being raised by humans has no relevance to Player Orcs having posture customization options. The reasoning is unsound. Since Blizzard has implemented this feature with zero lore explanation, we can infer that Orcs kept a hunched back due to a technical limitations and overlooked customizations, instead of assuming the Orc hunch is a fixed visual identity.