Yes. Since it is legal for a defender to jump straight up to obtain legal guarding position, if he takes off from inside the RA and jumps straight up, he is still in the RA and a block should be called. If he takes off from inside the RA and jumps forward, causing him to be outside the RA, he is no longer legal and a block should be called as well.

If he maintains verticality while jumping within the RA to play defense it is not a block.

secondary defender rule says player can't establish LGP in the RA "for purposes of drawing player control foul…." if I'm jumping to block your shot from the RA and there's body contact you might call the foul because of body contact but not simply because i was in the RA and body contact occurred.

The call in this play was a player control foul because the offensive player used his extended arm to push off the defender. Therefore, in regards to this play, your statement above is incorrect. Unnatural extension of an arm, leg, or foot by the offensive player is one of the exceptions to the RA rule.

So let me ask a play then:

A1 drives to the basket. B1 is a secondary defender who is located in the RA. B1 jumps in the air maintaining verticality and A1 plows him over. What's the call?

I agree with that statement and its application to the play mentioned. I answered in a general sense about a defender taking off inside the RA.

It's a PC on the Men's side....defender is not in the RA trying to draw a charge, they are playing the ball.

fumble.
no call or pc if he did use his arm to clear out.

rule wording says secondary defender can't establish LGP in the RA "for the purpose of drawing player control/or charge…" it goes on to say the RA rule does not prohibit the defender in the RA from trying to block the shot.

the purpose of the RA was to stop players from setting up to take charges near or under the basket. the rule specifically allows the player to jump to block the shot. and he's not doing that with "purpose of drawing a charge.."

so if he gets blown up by the offense, when he's not trying to get blown up by the offense, i think yo call the charge. that's just my thought from reading the rule etc. if the guy is truly trying to block the shot and does nothing else wrong.