It depends on why you want to learn a language. If you need to just for working a certain job then yeah we can remove the need for some jobs to require you to learn a 2nd language, but if you want to go market your business globally or live in another country and really get a long with people you probably don't want to rely on just a translator. It would still be very useful, but showing off you can learn a language or play an instrument kind of builds confidence in you that using a translator doesn't, so there will be value to that probably forever.. also sports.. as silly as they are ;)

It's kind of like all humans are in a constant show off contest and that won't ever change much, so some of those benefits will always be marketable and thus in some level of demand.