I thought "bait and switch" was illegal?
Given how popular this product has been, they absolutely anticipated year plus wait times between signing up and installation. And knowing that, I am 99.7% sure they put something in their contract about being able to change system configuration options (like if they no longer carry 600w panels and need to redo your configuration using 750w or something), and that they could change the price all the way up to time of installation.
And if that exists in the contract, then it's not bait and switch (especially considering that is limited to "Advertised price" and Tesla never advertises an exact price for their solar products, just gives a quote once you contact them).
It's still a super shitty thing to do and I hope it's a PR nightmare that costs them more in stock price than they ever would have made from gouging their customers (very unlikely, but in a fair world this would happen).