2x2PT has been 1.25x1.25 for as long as I can remember (10 years or more). It’s only the pressure treated deck stuff for railings. This does not apply to the rest of the 2x lumber, as those are still 1.5 actual. I got Simpson corner 2x2 brackets for crazy cheap way back but ended up not really using them. The 2x2s are warped to hell and a ripped 2x4 was too big in the original 2x dimension.