The duplication tool that hoppers were disabled for still works. I tried a slightly modified version of it for myself today in 1.11.2, it works perfectly. Infact, the more items I use the more I get in my inventory (which are drop-pable) Friendly note to everyone who wants hoppers enabled. and no, I will not share the glitch.
Cyp has mentioned a little bit ago he probably won't add hoppers back at all, no matter if there is a fix.
Because he doesn't want to risk it. I believe the cons are more serious that the pros at this point. You don't know how a plugin may interact with another too. Adding plugins must be done carefully. These fixes may cause other bugs. I think being safer rather than sorry is a good reason.
He, in a thread I remember, said that he was considering that he would add them back since he thought he fixed all the bugs. that's why I posted this