Surgical masks weren't in "not proven" territory at any point. Okay there might be some error bars left, but they are generally considered helpful. To the best of my knowledge no government has even attempted to deny this (which would be silly since half the airtime was people in surgical masks running around in Covid wards). These however were in limited supply.
The effectiveness of other masks was not so much "not proven" but to the extent that the lack of any standard allows you to say anything about them they just aren't anywhere near as good. In my mind their effectiveness in combating the pandemic is still well within 'not-proven' territory, but since this is somehow a partisan issue in the U.S. I'll limit myself to just saying that they shouldn't be considered a replacement for social distancing.
Right... just as N95 masks were proven against other non-coronaviruses.
Of course n95 masks only prevent entry through the mouth and nose, and particularly at the time we had reason to think those were other points of entry. So, saying that they were "proven" to work against SARS-CoV-2 at the time was simply false.
The effectiveness of other masks was not so much "not proven" but to the extent that the lack of any standard allows you to say anything about them they just aren't anywhere near as good. In my mind their effectiveness in combating the pandemic is still well within 'not-proven' territory, but since this is somehow a partisan issue in the U.S. I'll limit myself to just saying that they shouldn't be considered a replacement for social distancing.