Correct, and I am very much in favour of this for dinosaurs. The genus-plus-species convention arose in a context where it was being applied to extant animals known from (almost always) complete specimens, and where it was not unreasonable to make assertions about which species were naturally grouped(*). In Mesozoic dinosaur palaeontology, we are usually dealing with only fragments of a skeleton, and can very rarely say anything certain about a new specimen's position within the established phylogenetic tree â if there even IS an established tree. So it makes sense to give such taxa uninomials(**) rather than tying their names to an inevitably fragile phylogenetic hypothesis.
(*) whatever "naturally grouped" even meant back then.
(**) a new genus-plus-species pair in which the genus name is new effectively functions as a uninomial whose spelling happens to have a space in the middle.
In short, anyone who names a new species of an existing dinosaur genus is creating a hostage to fortune: there is every chance that the best-guess phylogeny will change, and then the name of the species will have to change to reflect it. Who needs that?
-- Mike.