Is Buddhism life denying or life negative?
Why your question and all the other similar questions you linked are not getting a direct answer, but a shuffle is because the Buddha did not give an answer for such questions.
You may read many shuffles here, but the truth is questions such as Begining of life, end of life (i.e. beginner and end of Samsara); or hypothetical scenario in which all sentient beings attain Nirvana will receive a cold silence as an answer from the Buddha.