Makes no difference if he, or others despised Slavery or not. His and the vast majority of Northerners, decision to do Nothing, about Slavery, was just as Supportive, to Slavery, as someone who thought it was a Positive Good. So, by default, he and the 85% of Northerners who wanted to leave it alone, were Pro Slavery. I will give you the 15% who wanted Immediate Abolition. That 85% was far more concerned about CW, and the Social and Racial consequences about ending Slavery, than they were about giving Negros rights.
Eric Foner is a Lincoln Apologist. However even he, recognizes how conservative Lincoln was on the Slavery Issue. Lincoln wanted the South subjugated, so he could get what he wanted, for his Section. That was a far greater concern of his, than ending Slavery. Slavery was alway something to be negotiated.