The term “Blitzkrieg” was never used by the German army officially or as a common slang. It was actually invented by English newspaper after invasion of Poland because the Teutonic “blitzkrieg” sounds more menacing and implacable than “lightening war”.
‘Auftragstaktik” Actually was and is widely used in the German army. It was never official lexicon, but had been widely used in the German army since the late 19th century, and continued to be widely used today, even though the post war German federal army added a different official term, “Führen mit Auftrag”, to describe the same thing. But the official term remain less commonly used in the German army than the unofficial one. Auftragstaktik was actually a pejorative term coined by conservative elements of officer Corp to deride the new command concept. The word was then embraced by the practitioners of the German bottoms up command concept.
“ Schwerpunkt” is a heuristic describing the somewhat nebulous concept of the focus of the battle, or the center of gravity of the situation. But in itself it does not translate to the flexibility and adaptability that characterized the command structure of Wehrmacht that led to repeated successes during the era of German Blitzkrieg. If there is a key concept that that made German flexible command work during Blitzkrieg, it might be “ Fingerspitzengefühl”, which is a complex term that mean something like a tactile sensitivity to the subtlety of the situation.
In modern tactical decision theory, it might be said the Germans always had a tighter OODC loop. The key to continued German success during blitzkrieg was less about rapidly bypassing enemy front and strike at his rear. That it would be good to strike at the enemy rear had occurred to the enemy too. But the Germans were along in being able to rapidly identify where the enemy front can be penetrated, and also how to flexibly penetrate deeply with limited forces without having to methodically reinforce their own flanks. So It was not just boldness. It was an ability to consistently get inside of the their opponent’s observe, orient, decide, and act loop. The Germans can collate information about enemy at a lower command level closer to the point of contact. The lower level command can quickly orient the observation within the larger command of which the command is but a part, make timely decision that effect the larger command, which in other armies must wait for information to travel up to the larger command, and then act promptly. They Germans won because they made bold decisions based on circumstances more quickly and better than their enemies.