Its definitly talked about in Western Europe, were it played a bigger role. Still I think its a sign, that speaks more for the long 70s theory. The leftists terrorism is no sixties leftover, its something new, showing the beginning of the seventies. The large protest-movements of the 60s fall apart; in Europe are they 1969 already gone, in the US they have 1970 with Cambodcha and Ken State their last hurrah. The extreme ideologes are left alone and go the way of terror, but the larger mass start their "march through the institutions". So I say political and social the 70s begin 1969.
My late uncle, who was a US Army officer in West Germany late 60s-early 70s (and married meine Deutsche Tante from Hambach), used to say that Europe was generally either five years behind (fashion and use of household appliances for example) or five years ahead (car design among other things) of the US during that period. I'd see the rise of leftist terrorism -- indeed the rise of terrorism in the specific contexts of the Marxist-derived but you could say "Marxist-dissatisfied" Palestinian movement and out of the fracturing of the '68 Left in Europe -- as a canary in the coal mine for the Seventies' arrival, it predates the real presence of "the Seventies" and thus confounds people operating at the end of "the Sixties" but it's one of the first symptoms. (That's a very English idiom -- I don't know about German or other Continental mining operations but British and American miners often took songbirds down into the pits with them, because the birds had highly sensitive lungs, and if they keeled over it was a sign the air was becoming unbreathable, so it became an idiom for the first sign of a big, dangerous change coming.) A classic example frankly is Das Attentat at the Munich Olympics. The whole concept there was (1) to embrace the likeable side of the hippy aesthetic as the antithesis of Nazism for a brightly-colored, idealistic, almost naively inclusive games, and (2) to focus security on the low-key diffusion of Sixties-style protest events and sit-ins, by doing things like passing out flowers to marchers and using dachshunds as police dogs. (Munich's mayor and police had done reasonably well defusing the local unrest there in '68.) They were completely unprepared for something like a trained team of goal-oriented terrorists operating on their own terms invading the compound even though the forensic psychologist the Munich PD had hired to help plan security had painted just such a scenario for them among twenty he laid out (one had Swedish neo-Nazis hijacking a plane and crashing it into the stadium, presaging that Seventies classic melodrama Black Sunday and also 9/11. Smart guy.) And even once it started, the political bigwigs involved thought it was all a Sixties-style armed sit-in as a "politics of the deed" in great-power diplomacy. They didn't understand they were facing the soldiers of a new age, with their own motives, tactics, agenda, and willingness to kill and die to break the existing system.
I think the two most underrated acts of political violence from the Sixties that helped make "the Seventies" happen as they did are these. One was the shooting of Rudi Dutschke, which did not kill him outright but crippled the one figure who might have found ways to hold a unified "Sixty-Eighter" movement together without losing the radicals to the Rote Armee Fraktion and Revolutionary Cells and so on. The other was the assassination (that's never been confirmed, but really, the same exact part was tampered with on the plane as in another near-crash he had two years before) of Walter Reuther of the United Auto Workers in the US, the one labor leader strong enough to back younger organizers' plays to buck the AFL-CIO hierarchy and align with the rights movements (minorities and women) on a common political front, and the one major union leader who could tell George Meany to piss off and lead at least a chunk of labor to endorse and support George McGovern in '72. Those two events IOTL had, as we say around here, great big butterflies.