Pjiang,
You can have all your imagination on the relationship between my ID and www.mylawyerwang.com. I will not comment on this.
But I can point out that the words posted on that website were from an even more authoritive interpretation (if you like to know the source, I can release it to you by personal email).
Let me make an example: person A has a 3-year H-1B visa. After working with H-1B for one year, he got I-485 related AP. He then went to China for a short time and used his AP to enter US. Did he lose his H-1B status? Since he did not obtain EAD, does he need to "extend" his previous H-1B in order to work for the same employer? If you answer both questions with "Yes", I would suggest you to give me a real-life example.
Since USCIS does not “consider a paroled adjustment applicant's failure to obtain a separate employment authorization document to mean that the paroled adjustment applicant engaged in unauthorized employment by working for the H-1 or L-1 employer”, in above example, person A’s 3-year H-1B visa is still valid and he can continue to work for his employer without procuring an EAD. It further means that his parole to the US with his AP did not affect the validity of his H-1B status. Otherwise he would have been required to re-apply a new H-1B (even the three-year limit of his previous H-1B has not expired) or get an EAD and this clearly contradicts with the Q4 answer.
Then let us go back to the original question: if an H-1B visa is and will be kept valid, does the use of I-485 derived EAD by his H-4 dependent invalidate the H-4 status? For this question, you keep making a wrong conclusion from a wrong premise. The wrong premise is your statement B “H-1 being H-1 as H-1 works for sponsor, after uses AP, not H-1” (sorry, I modified your words). Any person who can read Q4 answer will not agree with you.
One more big hole in your reasoning is: you equal the benefit/effect of AP to the benefit/effect of EAD. But for the exception on H-1 and L-1 visas, departure from the US absolutely invalidates all non-immigrant status. Using EAD itself has no bearrance on the user’s status if his status is otherwise maintained. There is no difference between receiving AP/EAD and using EAD/AP as to being AOS. You are in AOS after you file I-485 no matter whether you apply AP/EAD or not. For H-1/L-1, the key issue is: if you use AP/EAD and leave your original sponsor, you lose H/L status. If H-1/L-1 status is legally maintained, I saw no statute or regulation says that the dependent H-4/L-2 status cannot be maintained, or the H-4/L-2 status will be invalidated by using EAD. The nature of “dual intent” rule allows H/L to maintain their status while seeking AOS. It is totally ridiculous to conclude that enjoying AOS derived benefit (AP/EAD) will cost a price of losing H/L status.
If your argument is limited to guess “the taste of tone”, this would be my last response. Any sensible conclusion must be based on some research. You are appreciated for answering many questions here. But you are not appreciated for providing some misleading statements.