I'm gonna finally say it. This is gonna cause people to hate me. They will say I am uneducated and dumb. But I'm doing it anyway. I have a mon we should suspect test.
Yep. My credibility went out the window. If you wanna ignore me from this point forward go ahead and skip to the end. But for those who wanna engage with me, let's attempt to explore why this might, MIGHT, not be the end of days as we know it.
Yes, this guy is wicked fast. It's not called Deoxys Speed for nothing. It outspeeds a lot of the metagame. It's faster than Darkrai for crying out loud. But first off all, we gotta consider a couple things. For one, if it actually does invest in its speed to become a fast threat in the metagame that actually runs against the things you would want it to outrun, that means that it can't invest fully in either its offenses without compromising its bulk and vice versa. And if it doesn't invest in max speed, it will lose to a Deoxys that does invest in max speed. Furthermore, I would actually argue that it provides, hear me out, defensive utility. It's a good answer to stuff like Scarf Tapu Lele and Scarf Kartana since it can switch in on specific attacks like Psychic or Secret Sword and then force them out, with other scarfers being scared out too. And even with its blazing speed, in this era of booster energy and Tapu Koko being everywhere, the new Iron Boulder, the ever present Iron Valiant and even the rarer Iron Moth (who you would think you outspeed) all actually outrun you and can threaten to straight up eliminate you due to Deoxys Speed's frailty.
What about offensively you ask? Surely this thing is too much offensively with its special sets and with Tapu Lele's terrain everywhere, which even stops priority attacks (what are otherwise a great way to limit Deoxys Speed) except Rillaboom who destroys you. Well, Deoxys Speed is certainly stellar at this, nobody would say otherwise, there are some things to consider. For one, while 95 offenses are fine for it, Nasty Plot is needed to make this thing work as a true cleaner and that is a turn you need to secure safely. Deoxys Speed doesn't exactly switch into much and you only do this in emergency situations that can backfire. (Sure, you can switch into a Kartana's Secret Sword but what happens if it uses Knock Off, or a Scarf Tapu Lele that uses Moonblast, nevermind Shadow Ball.... you get crippled at the very least.) It also hates getting statused even when it uses taunt to block thunder wave or the like. You knock off a Zapdos only to get paralyzed by Static, for example. You don't have boots and get hit by toxic spikes as another example. Special sets are certainly strong to be sure, and expanding force is a hell of an offensive threat against unprepared teams. But lets stop and think. There isn't exactly a shortage of special checks that can reasonably handle Deoxys. What about physical sets? You know what it gets to boost its attack?..... Power Up Punch. Yeah, good luck sweeping with that amazing choice. You don't even get Bulk Up. And your physical coverage is the elemental punches, knock off and maybe extremespeed. Oh and because you don't have close combat you gotta settle for Superpower. Deoxys Speed probably works best on screens teams which love setting screens to allow for a nasty plot sweep on an HO team. And that could in fact be too much but with its frailty it's not exactly like you can't break it with good pressure. Is it really gonna run Iron Defense to avoid a knock off death? Congrats, you did that and now you lost a move slot.
In terms of hazard control, this is where I admit that it does a very good job. Other than Prankster Grimmsnarl and unevolved Sableye with Taunt, there isn't a ton that can stop Deoxys from getting hazards up quickly as magic bouncers (aside from Mega Sableye) don't like Knock Off, although Hatterene probably does a decent job at it (though it should watch for Skill Swap.) It can get Stealth Rock on the field reliably and even Spikes and/or screens with taunt to boot. But speaking of boots, many things run Heavy Duty Boots and/or defog to make Deoxys work go to waste. And being a dedicated lead you can see in team preview will be something a well prepared player will be able to deal with, or at least account for.
Now look, I am NOT saying Deoxys Speed is a bad Pokemon. That would be ridiculous. But I don't think it would be unmanageable. It would just be a very good Pokemon and would be a neat addition to the metagame. Could it be too much? Absolutely, and if so, we ban it with a quick ban or something. But if we are letting Darkrai run around OU, and that seems to be okay so far, testing Deoxys Speed doesn't seem unreasonable.
TL;DR Deoxys Speed would be a great Pokemon but wouldn't be overwhelming and we should consider a suspect test.