Yes of course.
Not my place to say this but - please don't release it the same week as World of Planes. Since World of Planes will be doing a massive advertising-campaign, then if you are releasing another plane-based MMO then the best time to release would be one month after World of Planes, so that people will still be hyped for plane-flight simulations. The other advantage is that instead of having your target audience leave for another game, it would be your game which is the distraction from World of Planes. From a social perspective, advertising before your competitor you would get a regular community, which would be (I exaggerate) distracted by the larger World of Planes community. Yet advertising after World of Planes you would be able to gain "free" advertising in the form of World of Planes players telling their friends who will already have the hype and interest in flight-sims. That's assuming you have a decent trailer. Usually games like Air Rivals / Ace Online, Altitude, Subspace Continuum, and Galactic Melee are overshadowed by the dauntingly small target-audience. Having played Red Baron, Wing Commander II, Star Wars: Battle for Naboo, and Subspace Continuum (in that order) while growing-up made me appreciate the genre. But all of the diehard fans who have gone to console gaming because of the old shooters like Star Fox and Star Wars being for console. Those who have stuck with PC were rewarded with stuff like Free Allegiance, Vendetta, EvE, Black Prophecy, etc.. As you can see, the trend of flight-sims has gone towards sci-fi, which is an unsuccessful genre in my opinion due to the low number of popular MMORPG games. To prove my point that your target audience is small: look at SEED, Star Peace, Stellar Frontier, Allegiance, StarKnights, Infinity Empire, Galactic Melee, Celetania (my favourite), and Beyond Protocol. What do these games have in common? They are sci-fi, and four of them are flight sims. The other thing that they have in common is that they are all closed (servers shutdown).
Now, I don't know anything about console. But if there aren't any flight-sims there, then it means that your target-audience is even smaller than that of the above games that closed down. Because I have not heard of any highly-popular plane flying games other than Air Rivals (a.k.a. Ace Online) and Altitude. So if you want "free" advertising you are going to have to ride the wave of the hype towards this sub-genre generated by World of Planes' own advertising campaign, and then derive "free" advertising via the World of Planes players who are referred to your game by their friends (i.e. "I am playing this game that's like World of Planes"; response: "Oh World of Planes is good, therefore I have a basis for being at least somewhat interested"). You will still have a competitor, but THEY will have spent the money to make the sub-genre temporarily hyped, which will generate you free advertising. The alternative is releasing the game prior to World of Planes, attracting a few thousand players, and then receiving the "Soul Master" effect of releasing your game one week prior to a mainstream-competitor (Soul Master is a korean game which shutdown in North America because it was released one week before Starcraft II). Your other alternative is spending the time to make a good trailer, then setting up an instant-gratification oriented cash shop strategy, then hyping-up your website with fantastic promises of future-updates to your game (if you want to deliver on those then you should hold-back on some content or ship designs - assuming this is an MMO), and then message TotalBiscuit for your all-in-one advertising campaign. After that it's either a wild success, or a rapid depopulation of the servers followed by a slow failure as you notice that there is no further target-audience to draw upon other than the World of Planes players, who will soon return to World of Planes. I doubt you can do it, since (I assume) you are a small indie company with lack of experience in mainstream marketing, which relies not on how sh!tty your game is, but on the lengths you will take to pander to your cash shop users. It sounds sadistic, and it is. The gaming industry doesn't need quality games to be successful. It needs addictions.
And that is why I won't play unless you make a good trailer. Because if you don't have the marketing-sense to understand even the importance of making a trailer, then the community is definitely going to stay small, which means less competitiveness, and longer matchmaking queues.
That said, I have no comprehension as to how games like Wizard101 rose to mainstream popularity. In fact, I'm just a player who left University to go and farm gold on Entropia Universe while I struggle to make it in the blossoming ARPG eSports Community.
Yes I'd like to play, but my point is that it doesn't matter how good your game is if your marketing is unsuccessful (assuming Sky Legends is an MMO).
Some dry humour which you may find relevant: League of Legends purposefully releases overpowered cash shop champions so that they can nerf them publicly in response to the criticism from people who are unused to dealing with that champion's skillset (and not necessarily the fact that they are slightly overpowered; the reason for the buff is so that the company can nerf the champion without making it underpowered). An interesting detail.