The search deal is indeed expiring in a few months, but also neither party has said whether it'll be renewed or not, so it's not yet time to assume it won't be.
Ok, that's fair.
pbhjpbhj's comment did predicate the speculation with an "If". And Mozilla has already had two rounds of layoffs this year ostensibly because of declining revenue. I think speculation on what will happen if the search deal is not renewed is reasonable.
I do appreciate pointing out that we do not know this will expire.
e: to your edit.
I'm not sure what is wrong with the question. My understanding is that the search deal is expiring and is the source of most of the FF related revenue.
If that is not the case I'd like to know. It seems like a reasonable question.