If you're worried, stock up on some 3DS while they're still hackable. I don't think they'll actively attack it, but they are certainly attacking homebrew and making hacking harder on newer firmware. If you wait to update, you should be fine.Okay. I still look out for the odds taking place of that happening tho. I am one of those kinds of people who worry a lot and think the worst case scenarios will happen almost all the time. :/
Unless Switch hacking takes off and the devs all switch to the Switch hacking. If that happens, Nintendo would be too busy worrying about the Switch to care too much about the 3DS.