remember when GW got back into BB, they decided to make a tweak to improve the human catcher.
Cyanide/BB2 had been using the 8238 catcher for quite a while, and the human team was doing pretty well with them. Which is why it was a disappointment (to me) that GW went with 8237 60K instead. To my mind a 10K Price reduction doesn't really do much to make the player more useful. And the people I've recently talked to WHO are playing humans are also underwhelmed.
Now - GW can do whatever they want.
But the reason they gave for keeping AV7 was that the miniature was less armoured and did not look like AV8.
And here's the ting: I just can't see any difference armour-wize between the Human Thrower (AV8) and the Human Catcher (AV7)

The catchers could have been AV8 just fine.
Cheers
Martin