That makes a lot of sense. Although expensive I think they should at least perform a regional genetic testing program (if one can even be reliably performed) on the youngest generation, to gauge what subspecies genetics are present in our population. Because from the sounds of it we might only have 2, Western and Central. It would be a good long-term plan (over the course of the century) for the only new imports to be pure Western Chimps, with the goal of a majority Western population by say 2080.
With that majority being either majority via hybridization, for example, most chimpanzees in the region would be at least 75% Western genetically. Or the more ambitious majority via segregation, where there are two distinct populations a larger pure Western chimpanzee population (breeding) and a smaller relic hybrid/'generic' chimpanzee population slowly being phased out. I understand it's extremely long-term but a distant goal to aspire to is better than just increasing the hybridisation when we have the opportunity not to.