There are two reasons why this isn't a problem. First, Fedora is not, in general, conveyed as part of a transaction in which the right of possession of a User Product is transferred, so it doesn't apply to (most) distribution of Fedora.

Second, this clause only requires the provision of information that is required in order to install and execute modified versions. That could simply be instructions on how to disable Secure Boot, or how to enrol your own signing key in Secure Boot.

What this clause prevents is shipping Fedora with hardware and without any facility to either add a user key or disable Secure Boot on that hardware. I don't think Matthew is planning to do that.

On the other hand, I'm no more a lawyer than Matthew is, so I could have misinterpreted everything.