So if this concept design was released instead of the one we have now, then Google is copying from their homework from their Chinese classmate.
An image surfaced over at Weibo stating on what appears to be one of the concept designs for OnePlus 7. As seen in this image, the OnePlus 7 was supposed to have a cyber-looking bar-like design just like the Pixel 6 series
Though the OnePlus 7 has a good design, it felt lackluster in contrast to the previous Pixel 6-like concept design. It made the original OnePlus 7 look like every other typical phone in the market.
The fact that the concept design only surfaced now may not be a coincidence. In addition to this strangely similar design, there are four cameras at the back, which is double than the original OnePlus 7 and is also uncommon back in 2019, as most phones back then had a maximum of three cameras, and most midrangers had two. According to the OP, the OnePlus 7 concept was designed in 2018.
In a tweet, Google confirmed the existence of the Pixel 6 series. Its design is strikingly similar to the unreleased OnePlus 7 concept (which means Google copied OnePlus, and not the other way around *gasp*). The phone comes with its own proprietary chipset called Tensor and comes in dual-tone finish. The Pixel 6 Pro has a triple camera while the base Pixel 6 has only two.
The Pixel 6 series is expected to arrive this fall, approximately between August and September. Other phones with a similar design include the TCL 10 series and the TCL Plex, which were both released in 2020 and 2019 respectively.