It was probably not done to keep things simple.
After all, a Rifleman has autocannon-5’s and large lasers that can flip, but two medium lasers that don’t.
Now, calculating that twice to get the
stats for firing all that rearward is one thing. You would create a new Special Ability, and then list the three damage stats all down in the box at the bottom of the card. But, then what is your forward firepower? You would need to list those numbers as well.
Suddenly, this is starting to make a stat card look wonky and complex
I think the discussion at the table ended with the feeling that flipping arms is more trouble than it’s worth, so Alpha Strike doesn’t have that ability. It’s not because the mechs suddenly can’t do that anymore, but because the game is meant to be quick and simple, so it got axed.