Fare class realignment happened last November. BA dropped some booking classes from economy and moved them into Club and WTP+. For example, the class hierarchy in Club fares now runs J C D R I, with R being the added class. This allows BA to set an intermediate fare between I and D. My guess is that they've reduced the number of seats sold in I and pushed some into R, thereby increasing revenue. Similar change in WTP where the hierarchy now runs W E T, where E is the additional booking class. There were then some changes in economy which preserved the same number of price points.