The people cheering this change as part of their “class fantasy” of a “guy with a bow” will tell you to simply switch specs to Beasts to handle other content. That will likely be the approach you will have to take.
Their position highlights the absurdity of their “class fantasy” argument. In this thread one of the more vocal proponents of pet deletion readily admits using his pet and jumping specs as it suits him. The investment in the “class fantasy” is actually zero.
The real hang-up here is, quite literally: Occasionally having 3 seconds of downtime in dungeons. That’s it. That’s the argument for just chucking one of the fundamental attributes of the class, non-dungeon utility, and the “class fantasy” of many other players into the shredder. So that they get 3 seconds more uptime every 10-ish minutes or so.
The true hilarity will be some weeks after launch when Blizz “tunes” the spec and nerfs it into the floor for reasons, and the people arguing “class fantasy” jump to the hot meta and drop MM.