I don't think Google is free, not for Tesla. We often think mistakenly that Google products are free, but that is only if you are the product that they are trying to sell. For example, search or even maps is free to most consumers because they are trying to sell your clicks to advertisers. The moment that you can no longer be a product, say you are using their maps to build a different product or on your internal website, Google charges you a lot, on a per use or per API call basis. Look up enterprise licensing terms and you will see.
I suspect Google will charge Tesla a f-ton of money if they want them to use their routing, unless of course they let Google spam us with ads.