The changes in vestment styles came about more at a local level, and under the influence of church supply houses, who sell vestments. After WWII there had already begun a movement away from fiddlebacks and toward Gothic chasubles. Most parishes still had plenty of fiddlebacks right up until Vatican II, but, new vestments purchased were more likely to be traditional-looking gothic, rather than fiddleback, in style.
The liturgical reforms as experienced in most parishes caused the Mass to look quite different virtually overnight, and with that the church supply vultures came swooping down, pointing out the need for a modern-sounding and modern-looking liturgy to have modern-looking vestments. There quickly developed a great desire to shed fiddlebacks, which became associated with the “antiquated” Latin Mass. :banghead: This trend was initially more intense in America than in Europe, but eventually spread. Since most newer Gothic vestments were of inferior quality material and workmanship, they also cost less–a fact that was highlighted by the suppliers, wishing to tap into the egalitarian spirit that was in the air at the time. :love:
The changes to liturgical and non-liturgical pontificals came about in 1968, and that pretty much sealed the fate of fiddlebacks, until the indult came along. Now most suppliers sell them again, even if in limited numbers.:bowdown: