Hmmm, I can see this definitely being a threatening glass cannon sweeper in UU, but I think its frailty, lack of notable Priority resistances and reliance on setting up SD (and reliance on Flying Gem to do any meaningful primary STAB damage) will keep it from the tier of the big boys. Oh, and Aegislash, perhaps the most notable OU-level Pokemon of the new generation, completely walls it and gets to setup on it for free... not good for the Hawlucha user.
As an analogy of sorts, you guys remember Alakazam before it got Magic Guard? It had a worse typing, sure, but it had perfect coverage, considerably more power (though on the special side), slightly higher speed and similar pitiful bulk. Still shot down all the way to RU simply because of frailty and inability to fend off priority users.
I wouldn't be surprised to see Hawlucha at UU, thanks primarily to the noted presence of Aegislash, but I don't really feel that the Alakazam comparison is that apt. For one thing, Alakazam's 55/45/85 defenses are considerably worse than Hawlucha's 70/80/70 defenses. This is especially true because all of the notable priority users are physical attackers, and because Hawlucha, unlike 'Zam, isn't prone to being trapped and killed by pursuit users.
Second, whilst Alakazam had and has far superior offensive stats, the difference is mitigated by Hawlucha's access to superior (both in type and in power) STAB attacks. Alakazam worked with Psychic (90 BP, 135 with STAB) and Psyshock (80 BP, 120 with STAB), with its next strongest move being Focus Blast (120 BP). Hawlucha has Acrobatics (110 BP, 165 with STAB) and Hi Jump Kick (130 BP, 195 after STAB). Even if you don't factor in the superior coverage that those two moves have in the established metagame, that's a considerable difference in power, and it goes quite a ways to compensating for Hawlucha's lackluster offensive stats.
Third, Alakazam's typing coupled with its poor defenses meant that it had very scarce opportunities to switch in, and had to be played as a revenge killer. As a psychic type, 'Zam's only notable resistance was to fighting attacks, many of which were so beefed up that they could 2HKO if not OHKO it anyway. Hawlucha's defensive typing isn't great by any means, but it does provide him with useful dark, fighting and grass resistances, and an immunity to ground attacks. When coupled with more passably decent defensive stats, he actually has the ability to switch in on certain OU pokemon if the player predicts well. As mentioned before, it's also a lot harder to revenge kill, since it has decent defense and a natural resistance to pursuit - something Alakazam really struggled with.
I'm not saying Hawlucha is definitely OU material, but that it simply isn't the kind of Pokemon Alakazam was - in any real, meaningful way.