@pokemoiso Aromatisse isn't meant to be put into every deck. Obviously, you wouldn't put Aromatisse in Primal Groudon or in Metal, but it helps in a few decks, like you said. Now about OHKOing Pokemon, I don't agree with this too much. Sure, M Rayquaza, Primal Groudon, and M Tyranitar are all Pokemon that are playable (Ttar is a speculation) and can do easy one shots, but the format does not rely on just those decks. What about Metal, Seismitoad/Landorus Bats, Manectric Variants, Primal Kyogre, etc.? I do think that Max Potion has lost a part of its shine from a few formats ago, but it isn't suddenly unplayable because of Mega Rayquaza. If your opponent is gearing towards your Aromatisse, then you probably didn't set up right. I almost always try to get out 2 spritzee on Turn 1, and if I can't I make sure that when I get out an Aromatisse it isn't alone (AKA I have a spritzee benched in case of a Lysandre). Regirock is to stop your opponent from taking away your energy.
As for your strategy against Metal, that's pretty cool. I usually have a 25/75 win ratio without any techs, but your way sounds interesting. The only problem that I'd have to point out is that with the changes, you only win 2 matchups that give away wins to other matchups. The deck will almost definitely lose to Primal Groudon and Primal Kyogre. Kyogre beats you because you aren't moving around energy on Pokemon and healing; Groudon beats you because you can't discard/attach head ringers to it and energy is all condensed on Pokemon that Primal Groudon can Lysandre up any time they want. Sure, you solve some problems when you take out Aromatisse, but you create new problems without it.
I do not think Aromatisse will be dead next format, but different. I'll compare it to Dark decks. Originally, Dark decks relied on Dark Patch and attaching a ton of energy to Yveltal-EX to make big OHKOes. Nowadays, people use baby Yveltal to power up Yveltal-EX and soften up the defender for a a 2HKO. Likewise, Aromatisse will have to switch to a hardcore offensive deck to possibly a Hard-Charm/Jamming Net defensive type of deck. Lastly, there is still healing, with AZ, Cassius, and Super Scoop Up. With VS seeker you can reuse AZ and Cassius in the same way that you'd use Max Potion turn after turn.