So the way I understand the holocrons is this. As long as you play in the right format your stuff from that format is legal. So if we choose not to play standard. We can use all of our cards from Awakenings on right?

Right now, standard is everything printed.

In the future, after the core set for 2019 is released, you can play infinite format to use everything printed, from Awakenings on. Otherwise, standard will start with Legacies and Trilogy would start with the 2019 core set.