I am not focusing on sabbe sankhara dukkha, but rather, his explanation of the first noble truth. You are right in that there is nothing new in his explanation of sabbe sankhara dukkha – we carry out sankhara and put in a lot of effort to achieve desirable things, but it is concealed by the likeable things, since we see them as worthy. I quote from the sermon (16.01) – “Is it fun to be working hard with the sweat running down your face? But that suffering gets concealed with one thing for which the worldly beings would keep on striving.”
What i found intriguing is this (23.20) – jātipi dukkā does not mean “jati too is suffering”. Rather, it is Jāti api dukkhā” shortened to “Jātipi dukkhā”. He used “Api iriyāva” – Apriya meaning disliked. So “jati api dukkha” means disliked arisings is dukkha.
I have not come across any interpretation like this before.