I can't speak to anything newer than comet lake, but between my various HP elite books, elite desks, Dell optiplexes, latitudes, and Lenovo thinkpads, very few of them have shipped with bitlocker enabled by default.
I am quite familiar with HP itself, and in fact as I linked on the other thread they publicly claim that _all_ their laptops have Bitlocker enabled by default. Lenovo is the laptop of TFA, so they are definitely doing Bitlocker on their enterprisey laptops. My Dell Inspiron 5510 came with Bitlocker on out of the box, and perusing the Dell support site having articles about Bitlocker recovery as early as the WD15 docking station era, I am sure they are enabling it by default too.