Not to encourage this, but this has been possible for a while. There are other classes with certain abilities, too. I remember a Wrath dungeon (one of the Utgardes) where you end by dropping down into a pool by the entrance. Same thing. Always had to pay attention, and quickly click off the buff before landing.
Using a given ability is never really actionable. I know you may not see it now, being on the short end of it, but could you imagine the chaos if Blizzard would action players for using the abilities they gave us? Same situation with Leap of Faith, or dismounting with a passenger.
The Deserter Debuff is what it is. You can suggest a different system, but the fallback of “just remove it” is not an option, due to players abusing it in the past.
They won’t. It’s been their MO since they started posting here: pushing limits are far as possible without consequences. Even with the definition they give, it should be considered trolling or at least extraneous (as hashtags have no meaning here), but I’m sure the Blues have much more important things to worry about. Kind of a pick your battles thing.
Just ignore them (either forum feature or simply not acknowledging their posts). The attention is what they are after. Don’t feed it.