In the absence of any counter-argument, I will stick essentially to what I wrote in post #7 above (before having seen the paper) -- i.e. :
If
Cuvier 1829 and
Swainson 1830 are discounted, then the inclusion of
Oriolus picus Gmelin (syn.
Gracula picoides Shaw,
Dendrocolaptes guttatus Spix) in
Voigt 1831 (a German adaptation of Cuvier 1829) can be seen as having provided originally included nominal species for
Dendroplex Swainson.
Should Voigt be discarded too (this doesn't really seem tenable to me, but perhaps "wird das Geslecht seyn" (= will be the genus) could be claimed to be less completely affirmative than "bildet dad Geslecht" (= forms the genus), which Voigt used in a footnote associated to
Xiphorhynchus on the next page of his work...?), then the inclusion of the same three nominal species in
M'Murtrie 1831 (an American adaptation of Cuvier 1829 -- this appeared later in 1831 than Voigt's work), and later again in
[M'Murtrie &] Cuvier 1834 (a British version which, although not attributed to him, appears largely based on M'Murtrie's), would achieve exactly the same result.
Of the three nominal species included in these works,
Oriolus picus Gmelin was validly designated as the type by
Gray 1840.
Neither Voigt 1831, nor M'Murtrie 1831, nor [M'Murtrie &] Cuvier 1834, were discussed by Raposo et al 2018.
It was perfectly expectable that any original uncertainty about
Dendroplex (which resulted in the not-fully-affirmative wording used in Cuvier's 1829 text) would have vanished after
Swainson 1830 himself had called
le Galapiot of Buffon the type of his
Dendroplex, in a commentary addressing the content of
p. 351 of the main text of Griffith et al 1829, where
Oriolus picus Gmelin,
Gracula picoides Shaw and
Dendrocolaptes guttatus Spix had been given as synonyms of
le Galapiot. Thus there is nothing surprising in the fact that the wording associating these nominal species to
Dendroplex became more affirmative in later translations/adaptations of Cuvier's work.
In 1837, Swainson cited only
Dendrocolaptes guttatus Spix, but he did not call it the type of the genus, hence his action had no effect whatsoever.