The things learning A language (as in one) does to the brain is important, and due to concepts not being fully expressed across all languages, you could end up with a sum total that would be lossy at best. Also, the language you speak shapes your mind and how you are able to look at the world. There are things that the meat puppets served by those AIs would irretrievably lose in the conversion, and I'm not sure that we even fully understand what all of those would be until well after.

Right now AI development is like old 'solutions' to conservation problems by dropping in X or Y species. We will find many disasters, some that can't be undone, for each mild success. The rates for wild successes will be even worse. Humans are a natural system, as is their society, and our brains develop and have evolved to develop within that system. We have to make sure that we don't leave behind important information and development chasing developing ease.