So as I mentioned before, Half-elf heritage with the way it is written means that the Half-elf looses access to a method to gain 5ft of speed meaning that it is hard/difficult to get to the needed 40ft of speed to get the new level 9 elf feat. They also loose an easy access to the elf language without having to spend a feat or have more int? So overall:
5ft Speed increase: Lose a method to gain 5ft speed thus it is hard to reach 40ft speed that you could before
Elven language: Have to now spend another feat or have increased int to get
Trained in Diplomacy:You lose out on this "free" training. Have to spend a another method to gain it like a skill point.
Low-light:Earn it with the Heritage
Half-orc heritage is similar also where we lose access to certain things.
The devs have mentioned this is just a start but I hope they don't forget about it.