It varies a whoooole lot depending on preparation and beans but I’ve certainly had somehow sorta salty tasting coffee. One bagel place I used to go to every morning had especially bad, salty tasting coffee from the bitterness. I was tired one morning and accidentally used salt instead of sugar, forgot I had added anything except creamer, and didn’t think about how salty the coffee was until 3/4 of the way through it because of the aftertaste.
Usually pour over is far less bitter, the French press coffee I make isn’t salty at all but is bitter, moka pot coffee I make is neither bitter nor salty.
Coffee usually has no sodium in it so it isn’t literally salty, probably just the bitterness, or it’s just from the water source.
…Yes, I don’t believe that Mozilla will kill itself over that or potentially have someone commit felonies to leak info abt government surveillance and subpoenas. But FF is open source so anyone would see a backdoor or notice versions not matching. For user data FF Sync is, afaik, encrypted in a way that Mozilla can’t access.
The devs can just put their extension on GitHub or host it on their own website. Issue is just visibility.