Maybe, i doubt at test level it would be let go.
I can't tell you what the thought processes behind the rules are but i can hazard a guess. I think both situations are dangerous but only one is easily resolved through a rule.
By saying you cant jump into a tackle you remove the dangerous situation without really changing the nature of the game. By saying you cant jump to compete for a kick or pass you would necessarily dramatically alter the nature of rugby. So rule one out and protect the other.
No one jumps into a tackle. In almost every case they're jumping to try and evade the tackle.
The only real reason jumping is any more dangerous than any other way of entering a tackle is that there is more potential for the player to land past the horizontal, which is covered in another rule anyway.
The more I think about it, the more I think the attitude should be that if you're able to effect a safe tackle on an airborne player, go for it, but just know that if they land past the horizontal it's an early shower for you.
But that leaves attackers free to jump into tackles in the hope of milking a red card.
Hecked if I know the answer