Does homophobic in this case mean that I can edit the content of an article and the diff is directly applied to the crypt?
A trivial solution to this problem would be for the client to just download a copy of the entire Wikipedia database and pick out the particular article it's interested in. With a proper implementation of PIR, the server still needs to scan through the entire encrypted dataset (this is unavoidable, otherwise its I/O patterns would leak information) but the amount of information that needs to be sent to the client is much smaller.