I guess only time will tell. Google also had Nexus from 2010 to 2016. Who’s to say the Pixel line won’t see a similar demise (and as a tangential point, probably an abandonment of support) in the next few years?

With the Chromebook obsolescence fallout and the decision to extend software and security support for those recently, one would assume that the Pixel may be subject to similar thinking within Google. But the sales volumes of Pixel phones are a lot lower than Chromebooks. Google doesn’t seem to generally handle hardware quite well.

Nexus was just re-branded to Pixel, they didn't abandon Nexus at all during that branding change.

You can see the full OTA history for every device going all the way back to the Nexus S:

https://developers.google.com/android/images

Note that there's no weird gap around the transition from Nexus to Pixel, both were supported concurrently during the overlap.

I think it was more of a rebranding, at least from Pixel 2 and onward. Nexus devices were often primarily designed by another manufacturer with Google oversight.

That was definitely the idea behind the rebranding, and we're seeing that with increasingly more Google-controlled stuff like the SoC. But at first it wasn't that different from Nexus practically speaking.