At least with the case of Sandman, WWE can and will pay for former employees going to rehab if they are willing to do so.
Believe me, I blame Vince McMahons methods and I am a strong supporter of the fact that WWE needs to be forcibly regulated by congress since it's obvious they have no desire to willingly cooperate, but I can't place all the blame on the business.
Because if guys like Perfect, Mike Awesome ect. ect. really wanted to end their substance abuse problems, the option has always been there for WWE to pay their entire way through rehab. But it's from their own personal choice that they continue to juice themselves up and mix cocktails of painkillers and alcohol after they've already been fired from the company.
So the wrestlers themselves also need to take some personal responsibility and actually band together to force some form of change. If enough WWE superstars walked out and protested every show until they got benefits, WWE couldn't just sweep it under the rug and fire everyone. Especially since they fail so bad at building newer stars in the first place.