Transfiguration is traditionally celebrated in the West on August 6. In Sweden and other Nordic countries, the Lutherans continued this tradition. But many German Lutherans (Church Orders authored by Bugenhagen and Veit Dietrich: See Reid, The Lutheran Liturgy pp 485-86) moved the festival to the last Sunday before Pre-Lent. This is a good example of doing liturgical change the right way.
To start with there are good reasons for the change. First, it moves a feast that is very important in the Gospel accounts from an obscure time (a fixed date in the middle of summer which would only fall on a Sunday occasionally) to a Sunday observance.
Second, the move is internally coherent, that is, the festival fits this liturgical season better. In the summer the focus of the lectionary is on typical Trinity season topics or in early August around Trinity X on eschatology. The Transfiguration fits there well enough, but one can argue it fits much better right before the penitential season leading up to Easter. This is its place in the Gospel accounts: a glimpse of glory before it is time to "set His face toward Jerusalem."
Third, it places a major festival in a good position to send off the Christmas/Epiphany season and its joy with a bang.
Fourth, it does no harm to the other stories the lectionary means to tell. If this feast were in the summer and transferred to the nearest Sunday (as it appears was the custom in Sweden) it would replace a Sunday in ordinary time. The same is true with moving it to the last Sunday in the Epiphany season. So that's a wash.
So the change is well-thought out and beneficial. So far so good - but there is more reason to think of this as a liturgical homerun. The change was made within ecclesiastical jurisdictions, not willy nilly in this parish here and that parish there. Some jurisdictions made the change and some didn't. And that's fine. But where the change happened, it happened in unison across an ecclesiastical jurisdiction in good order.
I don't think this is minimized by the fact that the Missouri Synod currently lives under two different church years. Within the logic of the 3-Year lectionary, Transfiguration needs to come right before Lent since Pre-Lent is no more. It's better to have two different lectionaries than no lectionaries at all.