While Norton de Matos was an advocate of mass migration, I think it is nearly impossible for him to win, since the election was clearly rigged against him IOTL. Plus, keeping Portugal as a dictatorship means that resources are more likely to be allocated to the colonies, more people want to leave Portugal proper, and birth rates among Portuguese are higher (Salazar and Caetano did not invest a whole lot in education, and I tend to feel if Portugal was a democracy, more money would be allocated to education
Salazar did not invest much in higher education, but there was a push to increase the primary education even early in his rule. The literacy rate in Portugal increased from 32% in 1930 to around 75% in 1975.
Marcello Caetano did have a much more ambitious plan to modernize the country and education was part of this. He appointed Veiga Simão as the Education Minister, and in 1973 he began reform the education system in the country and opened new universities in the country.
Marcello Caetano was pragmatic for the most part and his actual political views were more in line with what today forms the Social Democratic Party in Portugal (Centre-Right). He expanded the social welfare and was in favour of integrating Portugal into the EEC. Also, he promoted Portuguese emigration to France and West Germany as the remittances from these emigrants became an important part of Portugal's balance of payments. He was hamstrung from liberalizing more than he did by the older members of the political apparatus, led by President Américo Tomás.
Also, it was later revealed that Caetano had toyed with plans to grant independence to Angola, Mozambique and Guinea-Bissau once Américo Tomás resigned (he was expected to do so in November of 1974 when he turned 80).
In Guinea-Bissau, secret discussions were being held with the Senegalese government to mediate between Portugal and the PAIGC. In Angola, the plan was to have the the Portuguese government create a rift between the government and have the Angolan-born Vice-Governor declare independence of Angola. Cabinda was to remain Portuguese. In Mozambique, there were various plans that included partitioning the country along the Zambezi river, to the North FRELIMO would be given free reign and in the South a multi-racial state would emerge ruled by a pro-Western government led by wealthy Mozambique businessman Jorge Jardim as prime minister with the support of South Africa and Rhodesia.
So in the end, I think Caetano was a pragmatist more than anything else. He wanted to modernize Portugal and even supported protesting students during his tenure as Dean of the University of Lisbon. The colonial problem was something he was too unwilling to solve, so he just kept on following the same old policies, hoping that economic growth alone would mitigate the political problems. He was more liberal than he was given credit for, he just did not have the fortitude to stand up to the Old Guard.