Not likely in a way that's worthwile I'd wager. you'd need a lot of cabling (likely easy to pilfer yet valuable due to copper) and labor relative to savings.
Aren't the Teslas themselves a much more attractive and viable theft target? Once you've protected the parking lot from car thieves I doubt copper thieves are a major issue.
I started some envelope math expecting this to be silly but I think the capacity might actually be significant?
In the past six years grid battery storage capacity in California increased about 10,000 MW, or 100,000 Teslas (using a high approximation of .1 MW per Tesla). Tesla has around 50,000 Teslas in inventory worldwide.