I think it is possible that OBS could make that nuanced argument in court: that what Fedora is doing here confuses consumers specifically because of how they stack multiple default repos and override the 1st party package. But it would hinge on whether consumers are confused about the product they're getting, and I think that's unlikely to succeed. Notably, I think the fact that users are going to the OBS project to report bugs is more likely to work against their case than for it, because it shows that consumers do accurately realize that the OBS Project owns OBS, not Fedora.

Trademark isn't only about the ownership of the brand. Its about who can use the brand on what.

By using the brand on something else, the reputation can be damaged

Is somebody using the brand on something that isn't OBS?

https://bazaar.launchpad.net/~mozillateam/firefox/firefox.ja... is the config for what becomes Ubuntu's firefox package

https://gitlab.archlinux.org/archlinux/packaging/packages/fi... is the equivalent for Arch

Both apply different configurations, use different versions of dependencies, and in Arch's case applies a patch to the upstream code.

Which of them isn't Firefox?

I worked for a company that sold high-end imaging equipment.

They had distribution networks, authorized to carry their brand.

But there were also “gray market” distributors, that would do things like resell foreign market gear, or devices that were separated from sales promotion bundles.

These were our brand, but the company would not support them. No hardware fixes (unless paid), no firmware upgrades, and no marketing support.

Often, the savings were minimal. It was expensive gear; even at a discount.

whichever one(s) the owner of the name "firefox" allows to be called firefox. Open source code does not automatically mean you get to use the name of the project in your redistribution of it.