While it's still a bit ambiguous, I think the re-write makes it clear that the Dez play would not have been a catch. If this rule was in place last year, I would have been okay with the call.
It's vague how long the receiver must hold onto the ball after initial contact. At some point, every receiver gives the ball to the referee. I mean, they don't sit on the bench for the rest of the game holding the football!!
I exaggerate to highlight that there's NO DEFINED END to how long the receiver must hold onto the ball. So by default, (follow me on this) down by contact rules apply. Since there's a lacking new definition, the only existing end of process must take precedence. Every process of advancing the ball or catching the ball in the NFL rulebook ends with "DOWN BY CONTACT"
There's rule is deliberately vague, there is no new concept defined. In verbal discussion by various referees in public statements, there's a hint of a new definition, but no clarity on it. So the rule will be INCONSTENTLY applied, using complete subjectivity.
And yet, there is no written language in the old or new rule that supports the receiver holding onto the ball after having caught it. So, BY RULE, Dez caught the ball.
The only silver lining in all this TAMPERING BY THE NFL, is that Dez's catch will now be known as THE catch, instead of that 49ers moment.