I genuinely think this is stupid. If you're worried about unverified flatpaks being a security risk so much so that you disable them from your software center, at least you could keep their reviews so users could at least know if the app can be trusted.
I love Linux Mint. What Clem and team have been able to do and keep on doing is simply amazing, but in this case, for that specific part of this new choice, I'll have to disagree.
I love Mint because it really is the best option for new users, however, they seem to be a bit of control freaks. I posted a comment on their latest blog to ask if they could include their data about the number of downloads per month, since they installed a tracker on their site in March. They only included the numbers of the first month, and then nothing. I simply suggested that they could have that data as part of their monthly blog update. They deleted my comment. Sometimes they give me vibes of Gnome's non-transparency, or at the very least, control freakiness.