True Polymorph, do you gain all of the creatures new actions such as Legendary Actions and Lair ones?

Thanks for quick reply. I have a question regarding True Polymorph, Do you gain all of the creatures new actions such as LAs and Lair ones?

— Apsco (@Apsco60) October 4, 2017

When you assume the form of another creature, you don't gain any legendary or lair actions that it might have. #DnD https://t.co/PDdsSyuhIB

— Jeremy Crawford (@JeremyECrawford) October 4, 2017