The text message plan change loophole has expired, as far as I know. The reason you could do that is the same for any change to the contract that you say "adversely affects" you. Read any cellphone contract and you'll see there's a clause in it that spells out how this works. They actually can't change the contract unilaterally without your approval, but by doing nothing after they announce the change, you ARE giving your approval of the contract change. The contract will spell out how long you have after the announcement to get out of it without penalty (usually 30 or 60 days).
Verizon will probably argue with you over what constitutes an "adverse effect," but the law is actually on your side. They can't change the contract you signed in any way without your acceptance of it. If you don't accept it, they can't punish you because they broke the contract. I had to talk to a couple of different Verizon phone representatives to get my ETF dropped, but they did do it. If necessary, you could point out that there's a massive class action lawsuit winding its way through the courts regarding the ETF, and that when they lose it, you'll just get your money back plus more anyway.
The downside of this perfectly legal way to end your cellphone contract for free is that you have to wait for Verizon (or whichever carrier) to announce a change to the contract. This almost always appears as a note on your bill.