The last tranche was in 2005/6, coinciding with the introduction of JPA and JSP 752, which sought to 'harmonise' pay and allowances across the Services. It was used as an opportunity to modernise allowances (eg removal of allowances for Governesses and Beagles - the latter being the canine and not, err, the prolific PPrune poster) but also removed useful allowances for those in extremely cold climates - eg Winter log allowance. DOMCOL leave was also reduced - by strealth and materially altering the TACOS of those to which it applied.
The redundancy tranche was never billed as 'the last' because, patently, that is not the case. The allowances, which required tri-Service approval, were also relatively generous in retorspect bearing in mind that they were compiled several years befor the fiscal free-fall. Sadly, I was in the bracket for redundancy but offered promotion several days before the drop-dead date, counched in veiled threats such as 'well, you just might not get redundancy...' even though the field in my branch was narrow and there were more slots than applicants...