I think you could grab from behind and tackle just fine. The defender probably needs to keep their feet a little more. I’m guessing we see it called frequently on the preseason, a few times in the first month and rarely after that. Teams and officials will adjust.
I’m assuming they’ll target the avoidable ones, similar to defenders landing with their full weight on the QB. There will be shitty calls, as with any penalty, but hopefully less than QB safety calls.