I think the fact that it came with OS 14.4 suggests that it was refurbished and repackaged. ..I doubt Apple would go through the cost and trouble of OS updating and repacking old stock in January 2021...especially given that OG HomePods were discontinued 2 months later. IMO, refurbished is better than getting new "old" stock from the original production run, as the issues presumably will have been repaired and you get a new warranty. Will they allow you to purchase Apple Care for it?..for $39 its totally worth it.
Why would a “refurbished” unit have a serial number indicating a late 2017 or early 2018 production date? I wouldn’t be surprised if the stock designated as replacements aren’t stored in larger crates (no power cords attached) for years, and then fully assembled, updated, packaged and then shipped.