So the post does have a tiny bit of truth to it, then goes wildly false.
As far as I know, Lincoln was not an abolishonist. He wanted to keep the status quo and allow southerners to keep their slaves and the northerners to continue to not allow slavery. He felt the Constitution protected the southerner's "property". The Union was what he cared about. I do think he was against adding more slavery in other states, and that's probably why southern states seceded.
Freeing existing slaves did come after an early loss in the war.
I'm just learning about all this now in a podcast, but I haven't completed the series so I could be very wrong. Or the podcast could be. It's American History Tellers.
I kind of see it as Lincoln was almost a modern day centrist democrat. Basically there was an abolition plan... that was going to take a very long time. IE rather than going with abolishing slavery, the plan was that no new states would become slave states, and overtime the non slave country would have the votes to abolish slavery. Kind of reminds me a lot of say healthcare goes on today.
and just like modern day republicans... the confederate states made it clear they'd rather burn down the country than accept a slow change from the status quo.