Thanks for filing the issue!

As per comment#0 it is understood that it is a feature request rather than a Bug, Hence marking it as Untriaged.

[Extensions Triage] Assigning to Devlin to respond.

The pre-installed items are largely serving as entry points at the moment.  I think there is ongoing work to see how we can provide a more appropriate avenue to serve the same purpose.  jawag@, do you know the status of that?  (+benwells@ might also have insight)

These are added for Chrome OS to ensure new Chrome OS users have simple access to these properties. They are added to new profiles that sign in so I don't think there is a simple way to remove them on non-Chrome OS.

There is work ongoing to provide the same capability in a different way (pre-installed desktop PWAs) but it is quite a way off and won't really affect the OPs experience.

OP: Is there any harm in having these? Once you remove them from your account they should be gone.

Sorry some of that was unclear. 

By 'a simple way to remove them on non-Chrome OS' I meant 'simple way not to add them on non-Chrome OS.'

> simple way not to add them on non-Chrome OS
How are these added in the code?  If it's through the default apps, couldn't we make them CrOS only?  (That said, I know at one point we wanted them for all desktop platforms - so that might still be the case.)

I wouldn't say that there is any "harm" in having them, but (on Windows) they are junk extensions that are nothing but a name and icon (they aren't even links).