I'm gonna go with a quite unpopular opinion around these circles, but while I do feel bad for gamefreak's employees, and designers such as James Turner, for the hugely disproportionate reaction to the whole Dexit stuff, as well as the toxic behavior of a part of the fanbase (which has been notorious), I can't really feel bad about people in management positions (such as Masuda and Ohmori) who handled the whole Dexit situation poorly from the beginning. Plus, I also think that the toxic behavior is in part a reaction to another incredibly toxic part of the fanbase who rush to defend the direction of Pokemon games no matter how poorly thought out some of the direction decisions are. When you see any criticism you have to a franchise being dissmissed as an exaggeration, it is easy to turn toxic yourself.
While I never expected a full pokedex at launch, smart franchise planning + the fact that it is 2019 and games can be updated, could easily solve the issue. For instance, it is likely that SwSh are not going to be the last pokemon games to ever be launched. For instance, suppose the long rumored D/P remakes are in the pipeline, and they are based on Platinum's pokedex which has 210 Pokemon. So those are 210 pokemon that are going to have to be made anyway, which could have been excluded from the initial batch of Pokemon in SwSh, and saved to be released at later dates as the development of the remakes progressed. At some point, they will have to future proof their models and animations, as the issue will only grow worse as new games are launched.
The whole backlash was due to a silly decision that people would be ok not being able to play with their favorite characters, when that is one of the central points of the franchise. So, whoever decided that or has the power to change this, by thinking of suitable alternatives but choose not do so, are to blame. It is a shame that the reaction reached such a toxic point, and that common employees have to suffer because of bad management decisions and reactions.