yes, this is very true, it’s a dilly of a pickle to be sure.
basically my reading is that
khīṇā jāti, vusitaṁ brahmacariyaṁ, kataṁ karaṇīyaṁ, nāparaṁ itthattāyā’ti pajānāti.
destroyed is birth, lived is the holy life, done is what had to be done, there is no further ‘this’ in ‘that’.
is the earlier saying, while
‘akuppā me vimutti, ayamantimā jāti, natthi dāni punabbhavo’ti
is somewhat later
to break it down:
nāparaṁ itthattāyā occurs
V 5
D 16
M 41
S 162
A 30
K 10
B 2
while (whoops, edit incoming not khīṇā jāti ) natthi dāni punabbhavo occurs
V 1
D 2
M 4
S 9
A 7
K 66
B 2
In DN it is confined to DN16.
So I guess my point is that by far the more common statement is by far the more ambiguous one, while the more definitive one re rebirth is entirely absent from the IMO early silakhandhavagga of DN, and is pretty rare everywhere else except for the Theri, Thera and Apadana.
fwiw.