Well Lincoln is rightfully being seen as less and less of a "liberator" as historical study progresses. Black slaves were defecting and joining the Union army in large rates, taking emancipation and remuneration into their own hands to great extent. The Emancipation Proclamation really was a formalization of an already undergoing social revolutionary process of self emancipation, and one that Lincoln only undertook reluctantly because his mission in fighting the Civil War was never in ending slavery but in preserving the Union. That's why he said if he could have preserved the Union without freeing a single slave, he would have.

This is a large reason why I find the "procession of heads" in ML imagery rather strange, but especially ones that are retconned to include these dork ass fantasies about Lincoln representing some radical Republican agenda that was really self consciously emancipatory. Lincoln was kind of a dumb shit milquetoast liberal tbh. And his political miscalculations and unwillingness to pursue a radical break with entrenched American institutions including slavery led to a lot of misery and injustice that persists to the present day.

Like if you want a procession of heads from the American Republicans, do like Thaddeus Stevens or something. Lincoln was just straight up not that great.