Many business class PCs shipping with Pro versions of Windows do not have bitlocker enabled by default. We have a few hundred laptops and desktops in the validation lab I work in and very few of them shipped with bitlocker enabled.
Name a laptop model and we'll check. But do check the other thread too, I think you'd be surprised. I was surprised too -- it is practically guaranteed that on a laptop with a TPM and modern standby, Bitlocker will be enabled by default. In fact, a Windows install will default to on, ignoring the OEM setting.
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.
As I mention on the other thread, I could believe Asus or Acer or some other cheap laptop disabling it because of gaming performance or whatever, but not the big brands.
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.
I don't know what to tell you. Only going off my own experience. Maybe things have changed since Kaby Lake. Most of my systems are Kaby Lake or older. I only have the one comet lake Dell and at this point can't actually recall how it shipped since I've reinstalled the OS several times at this point.