Not sure how lifting the review embargo early is going to help sales. Seems like a 'surprise' launch a few days early would generate more positive buzz.
It should help, since the game will get high scores regardless. That will reassure casual players and biodrones who are worried it could actually be poorly received by journalists.
The very existence of "review embargoes" continues to amaze me. The concept didn't exist in the 1990s or the early 2000s. It's a completely obvious ploy to keep potentially bad reviews hidden until developers have had the opportunity to con unwise people out of their money.
While I don't mind seeing unwise people get conned in general, I'm even less inclined to watch shit-tier developers profit from their shovelware.
There was no need for an embargo when magazines were the main source of mainstream reviews. Nobody could get a significant head start and the information was easily controlled. In the early 2000s the mainstream sites started to grow a lot and there was a period where you actually had the competition and less control by publishers, but it didn't last long. By 2003 big publishers were already doing it with the biggest projects, and Microsoft set the new standard for big hits with Halo 2 in 2004.
This Eurogamer article describes the situation at the time:
Fair play to Microsoft, though. For the first time in living memory a genuine worldwide embargo was set, giving publications such as this a genuine chance to compete on a level playing field - at least in terms of the publication date. Suffice to say that the same rules didn't apply to Doom III, Half-Life 2 or Grand Theft Auto: San Andreas, which have all been slapped with bizarrely unfair and unhelpful reviewing restrictions, which seem to serve no purpose other than to benefit the larger organisations. But rightly or wrongly, Microsoft didn't allow for multiplayer reviews, and inferred, in fact, that testing for the service was still ongoing right up until the last minute.
Video game media in the early 2000s was pretty much dominated by the few major magazines and websites, so it made sense that people barely talked about this. Although they were already common (with AAA games) in 2003-2006, it wasn't until 2007-2008 that it became more common for journalists to openly talk about them, mostly because YouTube changed the game and media consumption through the internet was growing in general. Today YT and Twitch turn that up to 11.
Back in the old days, the publishers could keep journalists on a leash, since the biggest outlets had privileged access and breaking the embargo meant losing a competitive edge, not to mention all the special treatment with parties, promotional stuff, paid trips, ads, etc. If somebody didn't play nice, such as writing a harsh review in some cases, you could just cut all that and tell your pals in the industry about how a specific outlet/journalist couldn't be trusted.
Streamers and youtubers are pretty much independent when it comes to revenue and editorial policies, and they're also much more numerous, so there's no way to keep a tight relationship within a closed circle as publishers and journalists used to. Most youtubers and streamers have audiences with no reason to care about how or how much of the game is being shown or described, and the game could be negatively impacted by competition in several ways.
Embargoes are also important for publishers in terms of social media impact. If you have your reviews and footage spread across 10 days, the game won't be trending nearly as high on Twitter/Facebook/Reddit when compared to a specific day where websites, youtubers and streamers are talking about or showing the game at the same time. A very high peak is much more desirable than a mediocre average, specially when the publisher itself can decide when that peak will happen.
Whether they're morally justifiable or not is a different question. I think some types, such as launch day embargoes, are definitely meant to deceive foolish consumers and boost pre-orders, but having no embargo at all means less effective marketing and potentially harmful content with false and/or misleading content. The most common embargo seems pretty harmless to me. You get a review copy a week or so before release, can't stream or show content past a certain point until the embargo is lifted, and after that it's all fair game.