Bonus Language appears to be the only ability that a character can only get at first level that requires a high ability score. That means that Intelligence is the only ability score that makes characters lose out if it isn't high from the start. It pressures players to put points in Intelligence at 1st level when there is no similar pressure to do it for other ability scores. Unlike racial traits that might be genetic that might make some Ancestry feats only make sense at 1st level, languages are learned. I don't see any reason not to grant the bonus language with ability boosts that bring Intelligence up to 14.