Yes, the usual suspects have signed the letter, and of course the usual snooty condescending reaction arises from the usual NCR crowd.   FYI, when someone disagrees with you, that's not "hate"--that's disagreement.
I can't comment on Amoris Laetitia because frankly it's so badly written I haven't managed to slog through it.  It does contain outright errors, such as its claim that the church opposes the death penalty, which is absurd.  Whatever Francis's gifts, writing clearly is not one of them.

And that's exactly what the 4 cardinals and other are asking for--clarity.  That's neither heresy nor dissent, actually.

It's funny how those who pretend to want 'dialogue' moan about 'divisiveness' when they actually get it.