[Idle speculation; not a systematic analysis]
A number of books are foundational to the EA Movement. I am thinking of such books as Reasons and Persons; Doing Good Better; The Life You Can Save; Animal Liberation; and Superintelligence. Ideas introduced or summarized in those books serve as both the intellectual basis of EA and as a common inspiration for EA-aligned actions.
Yet, for most people, there are nontrivial costs to accessing these books. True, many people could get them at no monetary cost from a library, though the ease of this probably varies with life stage (i.e., student or not) and geography. As a former EA student group leader, I know CEA was happy to reimburse the expense of getting some physical copies of our own, and that was excellent.
However, there have been many times when I would have liked to cite these books and have not been immediately able to because this would require a trip to the library (probably preceded by a waiting period) or paying money to download the books from Amazon or a similar service. I imagine others are in a similar situation. These costs may well inhibit people from first exploring these ideas to begin with.
This situation seems suboptimal to me. EAs value the contents of these books a lot, and their contents are free to copy on the margin. This suggests that the efficient ex post cost of accessing the content of these books should be zero. Unnecessary barriers to access could also deter potential readers and thus reduce the number of people who could be exposed to and convinced of EA ideas.
There are certain ways in which it makes economic sense to give some EA organization the right to distribute these books, too. There is currently a principal-agent problem wherein the rightsholders of the books (publishers, I assume?) have only pecuniary interests in promoting and selling the books, yet we as a movement have high, nonpecuniary interest in having those books widely distributed. Our longer time horizons than publishers may also lead us to continue promoting them long after publishers normally would.
I also imagine that for most publishers, profits are concentrated after release, whereas the value EA as a movement derives from the availability of these books is more constant over time. This suggests the possibility of exploiting different time preferences by buying distribution rights after the books have been on the market for a few years and therefore produced most of their expected revenue.
The main downside I can foresee is cost, and I have no idea how much such rights would cost. A cheaper way to acquire such rights might be to acquire digital-only distribution rights, especially since EA is hardly in a position to actually print and ship books (though this can in principle be contracted out). A digital distribution model also overcomes the barriers for people who are primarily interested in citing the books.
Note that none of this is a criticism of how the authors of the aforementioned books have chosen to publish them. I assume they have good reason for the arrangements they chose, and I know that some of them donate proceeds. This is simply an inquiry into whether such post-publication acquisition is desirable, as I have not seen this idea discussed before in EA. However, I would not be surprised if either the authors of the above books, nor would I be surprised if an EA charity considered this before and determined that it was not worthwhile.