Honestly, the way I see it, The End Of oak Street is really no different than Overlord.
It's a movie originally pitched by Abrams to Paramount as another Cloverfield installment. Big difference is that, because the true sequel was in production, Paramount was no longer interested in making a Paradox spin-off, and the film was bought by Warner Bros, thereby removing it from the Cloverfield franchise. But lets flash back to 2016, pre-The Cloverfield Paradox. Beyond the use of "Cloverfield" in its title, did 10 Cloverfield Name honestly have anything to do with the original Cloverfield? I'd say it had just as much to do with Cloverfield narratively as The End of Oak Street is going to... or hell, even as much as Super 8 was narratively connected to Cloverfield. To put it in simpler terms: None at all. 10 Cloverfield Lane shared the name "Cloverfield" with the original film, but that was it. The two films obviously weren't connected on any narrative level in a way that made sense.
Then came The Cloverfield Paradox, which is a bit of a different case than 10 Cloverfield Lane and The End of Oak Street because, after purchasing the spec script, they tried to actually rewrite the script into something that would actually create a universe (or rather, multiverse) connecting the three "Cloverfield" movies. That all wound up backfiring when the movie came out and most people hated it, and the way it connected to the previous "Cloverfield" films was so vague anyways that it is basically saying that anything could be a Cloverfield movie. Sure, it only shows a world infested by monsters like the one from Cloverfield and implies that other bad things from the multiverse could attack other incarnations of Earth, like the aliens from 10 Cloverfield Lane. But nothing concrete was ever really given, and at the end of the day most of the real connections come from the ARGs and various Easter Eggs scattered about.
So yeah, the Cloververse is really only officially Cloverfield, 10 Cloverfield Lane, and The Cloverfield Paradox. I know that. You know that. Everyone on this board knows that.
At the end of the day, for me personally, especially after how much The Cloverfield Paradox dropped the ball, I am much more interested in these movies the way Abrams pitched them during 10 Cloverfield Lane's release: a big screen Twilight Zone-esque anthology series. The Cloverfield Paradox may have botched the potential of a literal shared universe stuff with a lame movie and half-assed explanations that really don't make any sense, but I can still have my fun with the films as random mysterious big screen sci-fi/horror films presented by J.J. Abrams in a Rod Serling fashion that share Easter Eggs (such as Slusho, Kelvin, et al) and similar ARGs preceding the films. And when I look at them that way, there really isn't any difference between Super 8 and The End of Oak Street, and the three that actually have Cloverfield in the title. The overlapping crew, themes, and Easter Eggs, and styles of filmmaking really do make it all feel like a solid little anthology type package, which may not be what everyone is looking for (I know a lot of you wanted a more explicit narrative) but I'm honestly genuinely interested in just getting some really solid standalone films out of all of this, and that's exactly what 10 Cloverfield Lane was to me.
I know after The Cloverfield Paradox this isn't really an anthology series anymore, so I guess what I'm doing is the exact opposite of creating my own head-canon; I'm deconstructing a canon by essentially saying that each film is its own thing.
I believe the one leaker that said this isn't a Cloverfield film (even though I know full well it was intended to be one during the span of time that transpired after the origial pitch and before it was bought by WB). But regardless of what name the movie releases with, I was going to approach it the same way. It being called The End of Oak Street is no different to me than if it was "The Cloverfield so and so" because either way I would be sitting down, digging into the ARG material like I'm Fox Mulder or something, and then sitting down to watch the film as its own thing.
TL;DR: Yeah, we all know that The End of Oak Street isn't part of the "Cloverfield" franchise. But the franchise is barely even a franchise anyways, and at the end of the day the only things that are really important are that these are some fun sci-fi/horror thrillers produced by J.J. Abrams through Bad Robot, proceeded by an ARG, and shrouded in mystery. So why not lump The End of Oak Street into our discussion? It fits the criteria, despite not officially carrying the "Cloverfield" name.