For context, I only play mage decks in wild.
At first i was really hyped for this card, like 5/5 hyped, as aggro decks are the worst enemy of secret mage (Odd Paladin, i’m looking at you).
But after thinking about it a little, i’m really not so sure anymore. First, “after you play a secret” is harder to triger than “if you control a secret”. Cards like Mad Scientist will not help to see the full power of Arcane Flakmage.
Best case scenario, you can play it on turn 3 with Kabal Lackey. Most of the time it will be on turn 5 and 2 domages will probably be too little. Odd Paladin have Never Surrender and Murloc Shaman have Coldlight seer.
The new revealed secret, Flame Ward, is very good (4/5 or 5/5) and will probably do a better job as an AOE.
The body, 3/2, is really not that good for wild, 2/3 is way better.
There is already a 2 mana minion with secret synergy to consider : Sunreaver Spy. While not as flashy, maybe more powerfull.
An AOE effect seems strong but in fact doesn’t really feat in the Wild Secret Mage gameplay, which is finish your opponent with burst spells. It was also why Medivh’s Valet was so good and Cloud Prince will probably be OK.
So, all in all, i rate Arcane Flakmage 2/5 for wild and 3/5 in standard (but maybe i’m wrong ans this card is busted).

I totally agree with what you just said. Just for the context i am a top 100 legend wild mage player. I don’t see how card like Stonetusk Boar, Moonfire or Malygos are problematic for the game. They have intersting effects and consequently you can build a deck around them, I see this as good for the game diversity.

Moreover in wild Malygos isn’t the problem with Druid right now. You have 4 good Druid decks : Togwaggle Druid, Star Aligner Druid, Jade Druid and Malygos Druid with Star Aligner the best one and Malygos the worst one. When you look at the decklist tou can notice that all these decks are build around the same sqeleton with only the combo part changing.

The problem with Druid right now is the insane draw they have combined with the insane defensive capabity combined with the insane ramp. There is not really a single problematic card, it’s the combinaison of Ferocious Howl, Branching Path, Nourish, Spreding Plague, Malfurion the Pestilant, Juicy Psychmelon and others. Here an article about the problem of Juicy Psychmelon in wild : https://www.hearthstonetopdecks.com/melon-madness-how-a-single-card-has-warped-wild/ .

In fact, the article also hightlight the true problem of Druid right now for the standrad format : “What both Emperor Thaurissan and Barnes started has been exponentially translated to two cards of the Boomsday Project : Dreampetal Florist and Flobbidinous Floop. Both cards not only enable mana-cheating on a whole other level”. You have it here, mana-cheating on a whole other level. In one expansion you can put 3 cards in your deck with over the top mana-cheating potential.