well, in this text there is no any denying of rebirth after death.
I believe the core problem is understanding his two-languages approach. The “everyday language” doesn’t mean these realities are an invention.
At the beginning of that page, he explain this issue with another example using the Buddha, perhaps clearer:
“The first example is the word “Buddha”. As you know, the word “Buddha” in everyday language refers to the historical Enlightened Being, Gotama Buddha. It refers to a physical man of flesh and bone who was born in India over two thousand years ago, died, and was cremated. This is the meaning of the word “Buddha” in everyday language. Considered in terms of Dhamma language, however, the word “Buddha” refers to the Truth which the historical Buddha realized and taught, namely the Dhamma itself.”
you can see, he is not denying the existence of Buddha the “physical man of flesh and bone who was born in India”, the everyday language notion of the phenomena.
The everyday language doesn’t mean the phenomena is non existent.
Dhamma language is addressed to understand the experience according anatta. This is not a negation of the phenomena. As he explain in that text:
“The physical language is the worldly, conventional language used under ordinary circumstances and based on physical things. The metaphysical language is based on mental things. It has to be learned, studied, and understood. It is based not on the physical world but on the mental. I hope you can now see the distinction between everyday language and Dhamma language.”
not the same thing, because here there is only one language. No two languages. Maybe it could be closer if those atheist claim their own moral actions are the final nature of that god. Although in such case they couldn’t be atheist at all. I’m not expert in that god neither in his inherited atheist products. Although hope you can see the difference with this.
Regarding Buddhadasa teaching, to say the Rebirth doesn’t exist because there is the explanation with Dhamma language, it would be confusing Dhamma language with everyday language. Then somebody wrongly could say the Buddha never existed or rebirth never existed. This wouldn’t be right according his two-languages approach
Buddhadasa approach using these two-languages is different and it can be shocking at first. Although by reading carefully soon one can catch the point. It can be a powerful help in Dhamma.