I don't like this method of adding or subtracting, but they added one step to make it look even that much worse.
Every child should be taught what numbers are needed to get to the next or previous ten. Counting by tens (or hundreds, thousands, etc) needs to be ingrained because we are base 10 people. They need to memorize those simple additions and subtractions (going to the next or previous 10).
This particular example should have been taught as you need 8 to go from 12 to 20, you need 10 to go from 20 to 30, and you need 2 to go from 30 to 32. So, 8+10+2=20. 32-12 = 20. It gets them thinking about both sides of the equation now, instead of reinventing the equals sign when you get to algebra.
Yes, you need to understand conceptually what 32-12 physically means, but you also need to be able to just do simple math automatically as well. That is where quality teaching comes into play. You need to make sure that point is driven home, both concepts are needed. If teachers are on auto pilot, and saying, just do it this way (the conceptual way) because that is what is going to be on the standardized test, and completely ignoring ingrained automatic addition and subtraction, then they have gone too far on the other side.
TLDR, It seems educators got hammered for the "old way" of teaching math that produced little calculators, but some are correcting too far on the conceptual side now, and handicapping children by not giving them tools to quickly add and subtract in their day to day lives.