More like it
DID happen several times but it was
so insignificant and
meaningless that you barely noticed it! (in other words you reacted normally!)
*(we're talking about the "Firefox was updated here are the new features" tab which shockingly opens
after an update and
is mildly annoying BUT
not malware rotfl)
This latest release also had a pop-up that offered some new color schemes to try. I tried it (once) on my Windows gaming PC, and didn't find anything that I liked as much as Dark Mode.
Then I got the same pop-up on my new Macbook. And my old Macbook. And the Macbook that I use for work. Again, it didn't bother me as much as the OP, but I gotta admit that I got a wee bit annoyed the third and fourth time I saw it. I'll probably see it at least 3 more times... once in my the Windows VM that I use on my work PC, once on my wife's Windows laptop, and once on my daughter's gaming PC when I update it.
If I was still working IT desktop support or software QA, this is the kind of thing that would piss me off as I would see it dozens of times.