Yes, I am LCMS. Currently a seminarian. The Pew Forum is wrong. Like most people, they get very confused by Lutherans.
From the Reformation until the late 1700s, early 1800s the terms Evangelical was a synonym for Lutheran. To call someone a Lutheran was to call them an evangelical, to call someone an evangelical was to call them a Lutheran. A Presbyterian, Baptist would have been scandalized by being called an evangelical because that means your Lutheran.
All this changed with the 1st Great Awakening. The revivalistic movement which came from the Awakening called themselves Evangelicals. A movement that confessional Lutherans have always denounced as false and in error, and in stark contrast to Lutheranism.
However over time, this second definition of evangelical became dominate. To the point, the first is barely remembered. In Germany Evangelical is still synonymous with Lutheran. Most of the state churches don't even have Lutheran in their name they are just referred to as the Evangelical Church. When revival style Evangelicalism came to Germany they actually created a new word for them to differentiate them from Lutheranism.
This is why many Lutheran churches in North America still have the word Evangelical in their name. It refers not to the Evangelicals we think of today but the original evangelicals.