Context: Season 4 premiered on October 16, 2017, with the two-part episode "Heroes of Mandalore", and continued to air until November 13, 2017. The series picked up on February 19, 2018, after a winter break. Disney XD then proceeded to release two episodes a week, and the final two episodes aired on March 5, 2018.

Question: when does the star wars rebels finale air?
Steam of consciousness below:
The relevant information to answer the above question is: Disney XD then proceeded to release two episodes a week, and the final two episodes aired on March 5, 2018.
So, the answer is March 5 , 2018.