A sad day for me to see this happen as well, especially given how out of the blue the public announcement came. DP Review had a sizeable number of well known pros and highly regarded and talented amateurs offering incredibly good advice that made it instrumental in my decision making processes as I transitioned from film to digital SLRs in the early 2000s and the shift between brands that went with it. IMHO though, it was already in decline when Amazon bought it out; many of the pros and other highly regarded indivduals on the forums had already gone due to site leaning more towards the gearhead than the artistic/creative side of photography, smartphones were killing the compact camera market, and I suspect Phil Askey had already seen the writing on the wall at that point.
Frankly, I consider Amazon's stewardship only accelerated the downward trajectory; the forums were already in decline due to the prevalence of specification-related discussions, but Amazon *really* needed to stomp on the rampant and often highly toxic fanboi-ism that had mostly been the usual mild Canon/Nikon rivalry, but span out of control with the mirrorless and, later, the smartphone market-shifts, yet failed to do so. A *lot* of the remaining old hands left the forums, or even the site for more creative and/or skills centric forums, at that point, and with it a lot of the additional value the forums brought to the reviews. The accusations of review rigging, compounded by doubling down on the denials when the evidence was black and white (or rather green-cast), certainly didn't help either.
Despite all that, I still have a soft spot for the site and, while I seldom check, let alone post, in the forums anymore, I do check the home page for new articles every few days and read / watch many of the articles they post; Erez Marom's articles are always a pleasure to read and look at the images, for instance. Maybe a smaller, nimbler owner than Amazon might be able to take it over, relaunch it, and make a successful business out of its operation, but Amazon's decision seems somewhat final to me and doesn't leave a lot of time to put a business plan together, let alone do the due diligence necessary for a potential buyout.
Worst case, there are plenty of other photography forums, and The Digital Picture has some pretty detailed gear reviews, albeit not covering as many brands, if that's what you're looking for, but it just won't be the same and I can't help but feel we're about to lose an incredibly important, valuable, and even historic, part of the online photographic world once the site shutters for good.