Does anyone actually think battery day they announce "Hey! we are totally making all the batteries we need ourselves as of today!?
Because that's insane.
Likely Panasonic ramps up for legacy 2170/1865 cells for existing 3/Y, legacy dual motor S/X, and powerwall demand
CATL ramps for China 3/Y production.
And Teslas "own" battery lines start ramping next-gen stuff for Plaid S/X, Cybertruck, Semi, and Roaster.
Eventually if the Tesla-produced-cells thing goes really well and scales really well they can replace panasonic output- but not anytime soon (esp. if they're at all serious about not just ramping new vehicles, but also solar/PW installs)