Not Tesla but Nvidia announced their intention to do a stock split at their AGM, subject to shareholder approval. I could see Tesla doing something similar when the date for the AGM is announced including items up for vote, ie increase in shares for a stock split.I'm not actually sure they CAN announce a stock split that would involve issuing shares that are not authorized to be issued- what (surprisingly little) I've seen written on the topic suggests you can not legally have a split involving shares that aren't already authorized to be issued.
But I'd certainly be happy to see anyone with evidence otherwise present it.
NVIDIA Announces Four-for-One Stock Split, Pending Stockholder Approval at Annual Meeting Set for June 3
This was on May 21 when Nvidia was trading just under $600, they've since shot up to well over $800.