Not under 1201. They can form a copyright circumvention device without being subject to copyright themselves as long as they're used to protect an actual copywritten work (in this case the encrypted game images).
So with Yuzu's patreon funds, it's very grey at the moment, which is probably why Nintendo decided to take aim.
But regardless, if they "distribute" (ie, can be freely read off the device without special tools) the keys in the clear, it isn't used to protect anything.
A browser does not have the code to decrypt a switch ROM.
At the end of the day it's what can be proven to a jury.
In this case for instance, I don't think there's a decent legal strategy for Yuzu wrt "we didn't know the encryption on switch ROMs was a 1201 protected device".
I didn't know that, and I'm a software engineer. Good luck convincing a jury :)