Here's what Elon had to say about loaners in 2013:
www.tesla.com
Fully loaded Model S Performance 85 cars or Tesla Roadsters as loaners Tesla will seamlessly valet the loaner cars to your location $600 annual service now optional with no effect on warranty Unconditional warranty for Model S battery, even for user error Making Service Better Than Invisi
web.archive.org
Unfortunately, they reneged years later.
I've seen many accounts like the OP's, where Tesla's service was excellent up until Model 3 starting reaching customers in large numbers.