So, there seems to be some confusion on what will be happening with the character transfers in GTA:O. I've heard many saying that this only affects transfers from last-gen, but that is not true. ALL transfers will be stopped on March 6th, that includes next-gen to PC as well.
Here is a copy of the official R* article:
GTA Online Character Transfer Special Feature Shutting Down
Question: When will the character transfer special feature shut down?
Answer: The character transfer special feature will no longer be available as of March 6, 2017.
Question: What character transfers does this special feature currently allow?
Answer: Until March 6, 2017 the following transfers may be made if they are eligible: