Is this a widely accepted theory about the causes of these events?
No. The critituqes of Strauss and Howe relate to the failure of their hypothesis to explain its own data adequately, and the limited data pool drawing from primarily US experience. The rapid breakdown of the theory when it was brought into contact with its own claimed evidentiary base means that we should not accept it.
Contrasting explanations for the cluster of late 1960s revolutions that I am aware of tend to be Marxist in bent.
Economic determinism is a fairly useful card here, 1968 is generally put as the start of the post-Bretton Woods economic configuration, as crises in production became evident and manifest. The important question to ask is: why did it take so bloody long? Marx's 7 year business cycle, based on capital stock renewal, should have indicated an earlier crisis, such as the mild crises the Australian economy experienced 1945-1968 as a resource exporter.
One point is that the United States had chosen to reduce the return to capital as dividend / consumed profit, forcing returns to labour to keep up consumer confidence and improve the quality of labour, and spending loads of money on waste (war, space) as well as productive forced capitalisation (highway programme replacing the transport stock of rail, etc.). This was atypical in capitalism.
Another point is that the Soviet Union existed which forced a changed set of behaviours, the apparent possibility of workers taking over changed capital behaviour in the 1930 depression, and this changed behaviour continued until the late 1970s.
For this I'd suggest the Trotskyist economists and the debate on the long boom, Kondratieff, the Autonomist debate on the fragment on machines etc.
I would suggest that following out of the debate on the machines we also ought to reflect on the cycle of accumulation of class struggle. Autonomia came out of the Socialist and Communist background of Italy, the failed partisan struggle, and the reflection on these in the context of the new forms of resistance to the factories implemented in the North. So the post-war capital stock renewal created the forms of resistance that emerged in Italy in 1968.
In Czechoslovakia the failed post-war revolution, and the semi-modernisation of Stalinism, created the sentiment in the party that would back the sentiment in the working class, created by the same semi-modernisation.
In France, a similar structure of production in white collar work, with the expansion of the universities, combined with a radical discontent with the traditional left (Socialism ou Barbarie, Situationalism.)
In the United States the changed composition of the working class post war had led to a crisis in the capacity of the old unions to keep a lid on the plants, and a similar mass discontent with the armed forces (see the sociology in Radical Amerika, for example).
Similarly with Japan.
The outlying case here is China, where a more traditional explanation of the economic development of a soviet style society is useful, the "cultural revolution" was as the Great Purge was to the Soviet Union, in a Ðilasian analysis—it was the party sorting out its own house, removing any remnant of loyalty to external bodies such as the working class.
So the two key Marxist explanations are: end of the long boom economically, end of the Fordist-Taylorist control systems' effectiveness in their post-1945 form; with a minor explanation in relation to China of a Ðilas style new-class internal purge.