I work in this space (being purposefully vague), you are getting a customized image of some sort - PXE really isn't related in this way, that's just a method to get the image onto the destination disk. The official Canonical Ubuntu Cloud Images produced for use this way have the MOTD behaviour and snapd in place based on my exposure to them. https://cloud-images.ubuntu.com/
It doesn't put a "customized image of some sort" on servers, it literally iterates through installer steps with the autoanswers provided by preseed file.
You might say that it is customized since we wrote a preseed file. Well maybe, but it's not a "customized image". Also we didn't write any specific code to remove unwanted packages. It just doesn't install them. No weird packages like byobu :)
nod I'll go out on a limb and say "I think you may be somewhat in a minority in 2020" as many in my travels have moved over to an image based deployment methodology - it's not absolute and of course I've not been in every company, just the landscape in general. I wasn't aware Canonical had an "online PXE" flavour that you linked, TIL.
I say all this above, but I'm sure there are still shops out there burning ISOs to CDs (maybe USB now!) and hand installing everything - if I've learned anything, it's that nobody seems to agree on how to do stuff the same way. :) Each company is it's own beautiful unique snowflake full of their own design and deployment patterns.
The new format does seem much nicer to my eyes but I suppose tastes vary. A pain to have to change but it looks like good work and a new release is usually required some pressed Hackett anyway.
