At this point, the information we have is that this is not the case when the phone comes from Best Buy.
As mentioned in the presentation, iFixit identified the Pixel Visual Core to be the same as the one found in its predecessors, while Google has bolstered safety with its Titan M Security chip. Google didn't reveal the switching between the two South Korean companies for making the display panels of its Pixel 3 models.
We reached out to Verizon to confirm after seeing this reddit post about a Pixel 3 XL getting a "not supported" message when a non-Verizon SIM was inserted. "First, to protect Android from outside tampering, we've integrated Titan M into Verified Boot, our secure boot process". The new Titan M is built using the same type of technology that Google uses to secure its data servers, which makes it particularly robust. The folks at Android Central also ran into a similar error. This is a new policy from the nation's largest carrier, and is not limited to the Pixel 3 series. In their teardown, they discover that screen repairs are going to be a whole lot harder and Google may have taken out shares in a glue factory given how much adhesive is packed into the portable computing powerhouse. In Android 9 Pie, developers can use the StrongBox KeyStore APIs to store private keys in the Titan M chip.
If you do cop a malware infection, Titan M stops the code from trying to unlock the bootloader and alter low-level system stuff, according to Google.
On top of all that, Titan M's firmware can't be updated or changed until the user's passcode is successfully entered.
Before you go to Best Buy to purchase a Google Pixel 3 or Pixel 3 XL, keep in mind that all Verizon variants of the phone are SIM locked to the carrier, and must be activated first on Verizon before a SIM card from another carrier is inserted.