Mycellium can grow on the new grassless dirt block

I don't know if it's intended or not but mycellium can grow on grassless dirt.

Steps to reproduce :
1. Open a world.
2. Put some "grassless" dirt (you can get it with the command "/give @p 3 1 1") next to some mycellium.
3. Wait a bit (~2 minutes) until some of the "grassless" dirt blocks turn to mycellium.