No, they're all very literally the exact same thing. I see no distinction between them at all; they're all fundamentally the same meme repackaged for a new generation.
In the early 90's, conservative intellectuals were faced with a problem due to the collapse of the Soviet Union; they could no longer tar the left as unamerican by association with it. Political correctness, as a term and concept, was
pushed by conservative think-tanks in order to try and tar the entire left as part of a dishonest effort to push the conspiracy the that more fringe conservatives much less subtly referred to as cultural marxism.
More recently, the rise of Islam as the bête noire of the far-right necessitated a way to tar the left as sympathetic to Islam (again, in order to replace the red-baiting of the Soviet Union era.) "Regressive left" was concocted by the same impulse that led conservatives to manufacture the memes of political correctness and cultural marxism - in an effort to tar leftists as unduly sympathetic to Islam (and, therefore, intellectually suspect.) All of them also serve the same core role of reassuring right-wing libertarians (who find themselves, constantly, on the same side as genuinely regressive Taliban-style American fundimentalists) that they're on the right side by allowing them to construct a fantasy in which the left is the side that
really opposes free speech, free exercise of religion, and so on. (This is also why the people who cling most desperately to all three fantasies are right-wing atheist libertarians - again, they face a constant contradiction in allying with themselves with the religious right. These three concepts, while lacking any real grounding in reality and lacking any sort of statistics or data to back them up, provide an emotionally-comforting bedrock to the atheist right by giving them an out for their constant willingness to side with a censorious and illiberal religious right - the only way they can justify their position is by constructing a fantasy under which the left is even worse.)
It is useful to discuss them as manifestations of the neuroses of the American right and the various branding efforts they have used to attack the left throughout recent history; but none of them have the slightest connection to reality. They represent right-wing fantasies about how it would be useful to mislead the public into viewing their opponents, not anything even slightly real.