Cuba-US: Behind the Curtain

Cuba-US diplomatic relation is more a threat before it can be recognized as an opportunity. Because like Assad and Kim Jong-un, the Castro brothers need their power to be survived more than anything else and Russia and China are the only powers can officially and openly defend Cuba, Syria and North Korea dictatorial regimes. So the political orientation of Cuban government will not likely change after gaining some political points from the White House. 
It should be also added that Washington has attempted several times to carry out a coup in Venezuela, and Havana is aware of the fact and certainly feels concern therein, specially that the last Code Coup against Caracas was foiled right after Obama's call to re-establishing ties with Cuba. In such circumstances, Cuban political need grows toward its supporters containing Russia, not the US. 
Keep in mind, standing and acting for unessential social or political goals is allowed even in the darkest states of human rights such as authoritarian rule of Cuba, therefore Castro's daughter can be an activist for LGBT (and be a round the world traveler while other Cuban citizens cannot) but key changes are only possible through democratic elections like what the world has seen in Greece, something that is not available in Cuban government. 
Apart from what has been said, there are also external factors which send alarming signals on the establishment of the political ties. 
First, Putin regime has begun a new round of Russian diplomacy to maintain the hegemony of Moscow. Accordingly more points are given to allies and friends of Kremlin. 
Second, United States diplomacy is experiencing the weakest management over the past half century. John Kerry, the Center of God's friend has have the weakest performance among the secretaries of state over the past 50 years based on the recent survey of the Foreign Policy publication that was made of international relations scholars votes. 
And now, the White House officials should disprove this argument before taking any further steps, if it is not an Israeli project to detriment of the order.