Nodes will not come to 1.3, and Nimi will sadly be leaving development after 1.3 (besides releasing small patch updates after the main update). Materials have not been announced yet, and I doubt they will ever be added to MI, especially with the current game engine it uses, but it's not impossible that basic materials could be announced for 1.3.
Nimi's plate is overflowing with new features to add, so now, more than ever, large suggestions are not considered at all.