[Google Pixel 3 Questions & Answers] i5lee8bit:
I mean, I'm not complaining. But I was incredibly surprised! I bought the phone BRAND NEW AND SEALED, from the current sale on woot ($170), and yet was still intending on returning it after I realized I had bought a Verizon variant, albeit carrier unlocked. Yeah, it's only the 64gb version, but I literally just bought this for testing, and as a backup. Actually bought a P3 from a friend that was in decent condition. A really close, trusted friend too, but unfortunately it just happened that about a month later the battery started exhibiting the dreaded behavior indicating it was starting to fail, so I decided to pull the trigger on the sale, not realizing it was a Verizon model. I went into much more detail about it in my post on Slickdeals: https://slickdeals.net/forums/showpost.php?p=146850461&postcount=127

It's also pink, but I'm putting on the Mint colored Spigen Neo Hybrid case on it anyway ;)

So anyway, from all my collective knowledge about Pixels, and plenty of knowledge about (and hate towards) certain US carriers locking down devices, I wasn't expecting to be able to bootloader unlock this phone. Luckily I decided to open the box anyway and see if the OEM unlocking toggle was greyed out (which is what I fully expected!)... And it wasn't!? I still expected something, anything, to go wrong, but no, it actually successfully unlocked the bootloader (proceeded to factory reset as usual, etc)!! Unfortunately, it seems that the eSIM is still locked up and disabled, but like I said, for my usages as a simple dev'ing, testing, and/or backup phone, the eSIM isn't really important to me.

Don't think it matters, but I did this immediately upon opening the brand new phone, and it was on firmware PQ3A.190505.002 (May 2019, Pie). I mentioned it in my SD post, but the IMEI does start with 35, and checking it through Verizon's prepaid check system also indicated it as Verizon branded. I know that historically (on older Pixels, not even the 3, iirc), there was a [anecdotal] workaround where some owners would pop out the VZW SIM card before ever turning on the phone and they could then unlock the bootloader. Crazier for me is that I didn't even bother pulling out the VZW SIM card the phone came with before turning it on.

The only thing I can think, is that (and my memory here is foggy about the anecdotal posts) maybe when people were buying the phones from Verizon, those phones were actually turned on with then-active SIM cards, thus allowing them to "phone home" and permanently lock up the bootloader, at some point before ultimately shipping to the buyers. However, as these brand new Pixel 3's being sold are just leftover old, albeit brand new and factory sealed, stock, they were never turned on, whether at all or with active VZW SIM cards, at any point. When I initially turned on this new phone earlier today, since I left in the VZW SIM card included with the phone, I got a message pop up saying something along the lines of "we couldn't activate the device" or whatever.

So anyway, I wanted to say all of this because I'm always fascinated by flukes like this, where someone (me in this case!) is able to bootloader unlock a phone that should otherwise be completely unable to do so... Also attaching screenshots to show that it is indeed a Verizon branded Pixel 3 with the bootloader now unlocked. Note that it now shows current April 2021 firmware installed, but like I mentioned before it shipped with May 2019 installed from the factory, and I updated the firmware after unlocking the bootloader immediately after opening. Is there any explanation to this? Did I just get incredibly lucky? Does my theory in the previous paragraph possibly make sense? Or is there already a known explanation somehow and I just was completely unaware (and if so please let me know)?

final note: pics look like phone's screen is fuzzy because I haven't even removed the factory plastic wrap yet, lol. amazon glass screen protectors come tomorrow!

EDIT: LMAO! The listing on Woot now says in big bold letters, "The bootloader is LOCKED on these phones". Pretty sure it didn't say that when I bought it, so must be a lot of people complaining about it and trying to return! Not sure how I was able to do it though still... even if I couldn't, I would have just cited the lack of eSIM as my reason for return. Fully Unlocked != eSIM Neutered, lol.