From the Nano One PR:

"CEO Mr. Dan Blondal is pleased to announce that Nano One has entered into a cathode evaluation and benchmark agreement with an American based multinational auto manufacturer"

...and....

'Mr Blondal said, "We have added a major global EV leader to our pipeline of opportunities and we aim to develop this relationship into a long term commercial arrangement.'

The above together indicate an "American-based major global EV leader."  If that isn't Tesla, then I don't know who else would fit that description. 

As I've now been doing for months, I continue to speculate (please note this is still very much speculation) on agreements being negotiated between:

LAC - NanoOne - Sumitomo - Panasonic - Tesla

Incidentally, a recent Twitter Joe Lowry poll shows the following:

Ok sports fan, the weekend poll. What OEM was @NanoOne_NNO referring to in their recent announcement?

Ford    18%

GM      36%

Tesla   46%