Mean, if we can then understand each other without problem, I'd say then any language works.
True in a sense but there are languages that have features others don't.
plus all manner of other videos he has done, as well as the language side of the internet.
Plus if this is also going to be written language then other features also abound -- Korean, or at least the Hangul alphabet (there is still some legacy Chinese stuff in a few corners, and more historically), is written like it is sounded when spoken unlike English which... rather less so (would give example but we might frighten the knight's lieutenant off his island if we did that, all the blood from the wounded would not do well for such an iron hearted ally).
We then get a choice to add more features, understand more history perhaps (I find cold war history fascinating, harder to go for primary sources when I don't speak German nor Russian), save a dying language, do an experiment to see what the collisions would be (the wide varieties of English, French and other European languages for just a few hundred years, and then again with a collision with the internet, potentially fascinating to control that if this is some kind of nanobots give you a language option), or alternatively what the collisions would kill (if English then many would probably opt for it all the time owing to being so useful both on the then world stage plus entertainment plus whatever else and that would leave others to atrophy).
Language also forms a world view so you might want to engineer it for that to get rid of traits you don't like, or encourage those you do.