Here's how the Pixel 4a XL probably looked before Google scrapped it
Leaked Google Pixel 4a render
It certainly makes sense therefore that Google would at least think about releasing a direct Pixel 3a XL sequel, but what's unclear is the reason why the Pixel 4a XL was cancelled. We'll probably never know that, but assuming the handset would have ended up looking like a new eBay listing suggests, the key selling point is pretty easy to guess.
Unlike the single camera 5.8-inch Pixel 4a, the mysterious 4a XL would have probably housed a dual shooter system on its plastic back, although the imaging specs that never were are obviously kept under wraps. It's relatively safe to assume the Pixel 4a XL could have borrowed its two rear-facing cameras from the high-end Pixel 4 and 4 XL, which might actually explain why Google ultimately decided against bringing this thing to market.
The Pixel 4a XL would have had two rear-facing cameras
You don't want your budget-friendly mid-rangers to resemble your expensive high-enders too strongly, not to mention the Pixel 4a XL could have also looked a tad too similar to its little brother. Based on the same photo of a "replacement new battery back cover door", the 4a XL was designed very similarly to the Pixel 4a, including a rear-mounted fingerprint sensor, a headphone jack, and a nice contrast between the white (or rather "Barely Blue") back panel and orange power button.
Of course, there are no guarantees this is a legitimate spare part for what could have been the Google Pixel 4a XL, but at first glance, it definitely looks the part (pun intended). If for whatever reason you're interested in buying this, there are "more than 10" units available at the time of writing, priced at almost 20 bucks each and shipping worldwide from Shenzhen, China (obviously).
Things that are NOT allowed: