This stuff largely doesn't exist for Linux, so they're missing out on this profit for any Linux preloads. It's also why you see Linux preloads mostly done by more boutique PC builders -- they've already charged a reasonable premium on the build.
Realistically, the reason OEMs pre-install Windows has nothing to do with the storage space or even with the logistics for developing a "choose your os" program. It's that they get extra revenue from bloatware contracts.
Boutique PC or even laptop manufacturers are more than happy to provide Linux. They do not make enough machines to be viable for bloatware contracts, so for them it is often instead more profitable to get extra buyers by catering to niche user bases like Linux users.
and as a tech person, i would not care which linux distribution they choose. let the OEM pick one and use that as their differentiation point, if that's of any worth. ubuntu, fedora, suse, pop! os, whatever. it doesn't really matter, as long as there is an alternative to windows.
As an anecdote, every developer that I know and I personally use Windows or Mac laptops and desktops. 1 guy in the group has a linux setup, but primarily uses Windows or Mac. While most of us have installed Linux on a device at some point, none of us use it as our daily driver. I'm talking about a network of roughly 100 devs that worked together or are a friend of a friend that chat on Slack daily. Yes, it is a small sample size, but it is relatively representative of what I've seen from devs at all of my previous companies over a 14 year software dev/engineering career.
I don't mean to merely refer to this particular issue/non-issue. I refer to the entire industry pre-loading Microsoft Windows on every new computer as IF this were the desire of everyone in the world.
I'm not suggesting that there isn't a market for Windows, I'm suggesting that an industry-wide forced-Windows-ONLY world is bad for the market, bad for consumers, and probably bad for OEMs... If it's some shady Microsoft OEM contract FORCING this to be the case, let's see an example. Didn't anyone challenge it?
Why don't Dell or Lenovo sell 10-20% Linux laptop preloads? Surely one can understand that developers and plenty of other users require Linux not Windows, right?
Why are Linux preloads expensive and odd? Why are more OEMs not ALSO selling Linux preloads?
So annoying!