Imagine your friend that does not know anything about linux, don't you think this would make them not install the firefox flatpak and potentially think that linux is unsafe?
I ask this because I believe we must be careful and make small changes to welcome new users in the future, we have to make them as much comfortable as possible when experimenting with a new O.S
I believe this warning could have a less alarming design, saying something like "This app can use elevated permissions. What does this mean?" with the "What does this mean?" text as a clickable URL that shows the user that this may cause security risks. I mean, is kind of a contradiction to have "verified" on the app and a red warning saying "Potentially unsafe", the user will think "well, should I trust this or not??"
If "nearly every app" that people already use suddenly has a big warning on it, people will quickly decide the warnings are meaningless and start ignoring them, like Prop 65 warnings. Congratulations, we've moved the needle backwards.
You have to meet people where they're at. I finally switched to Linux when MS introduced a feature I wanted no part in (Recall AI), but I would have given up within a day or two if the transition hadn't been basically seamless. I was able to pick up right where I left off, using all the same apps I did on Windows ~~except MusicBee RIP~~, but now I'm in a better position than before, on an open-source OS instead of closed-source. Now there's a little less friction between me and better, freer software.
prop 65 warnings are indeed useless