I have
I found the siblings families of a few of my 3rd Great parents on both sides. Sadly, we haven't had the chance to talk and re-connect. I think for most - it's weird -- cause we have no knowledge of each other until the DNA matches and Census/family tree research.
One that isn't as far back as enslavement - was one of my maternal Great Grannie's (b.1898) -- her sister's family -- they are deep on Ancestry DNA. We have all reached out to each other - and work on our family tree together.