@Jetah Depends upon the purpose or driving force behind the particular sale...ie the sales goals. Sometimes they are a dollar amount, in fact, that's usually the case, but not always.
If the goal was to bring in more needed revenue for development purposes, than incentivizing current backers to up their backing would definitely be on the menu (as is, they can upgrade at the same discount anyway, so its not like your losing out here) BUT that is not the driving force behind this sale.
If the goal was to bring in more players to test the game, without always relying on affiliated systems to funnel players into an open alpha environment like they did with the last test, then you mainly want to focus on getting new backers into the game. They can't just open up the floodgates for free totally, because that would indeed cheapen the valuation of what the earlier backers put forth. Alpha and Beta Access were perks you got for being a backer of some kind, and when you could come in was tiered out. They are modifying some of that, mainly because they are modifying their entire Alpha/Beta Schema, and because they are already having to adjust their predicted timetable because of unforeseen circumstances (Covid-19). The do already do limited stress testing near the end of most of their Alpha sets, where they open the floodgates for a weekend to maybe a week, but that's nothing compared to what backers have had exclusive access to. The experiment with the other system to bring people in I assume failed so they are trying a different tact.
In any case, I tend to digress, as the purpose here is to get MORE officially sanctioned testers (not just people invited in through a 3rd party portal) they are going about this sale in exactly the manner they should be from a business standpoint. Business Consulting is what I went to college for, and advising on these kinds of situations is eactly what my degree program was about, well, this and how to rearrange systems internally, etc... (think the 'Bobs' from the movie Office Space, but with a tech-focus as well)