You can certainly acknowledge and own up to the role your church played in slavery and racism. Which is what these folks did. Granted, it is merely a drop in the proverbial bucket in terms of addressing religious hypocrisy, but every little bit counts.
Church history is freckled and asymmetrical as anything can be.
"Own up" to the role your church played assumes two unfounded and false notions:
1) That the fault is in any way yours. It's not. As stated by some other posters here as well as God on a few occasions, the sins of the father are precisely that- the father's, not the son's.
2) That the church is not constantly changing, usually to a point of being unrecognizable from what it once was even 50-100 years ago, Baptists included. Catholicism prides itself on being as faithful as possible to what it has always been throughout the generations and it isn't- it is very different from what it was 100 years ago, which was very different from what it was 100 years before that.
You don't "own up" to your church doing things from over a hundred years ago any more than I would "own up" any injustices, perceived or otherwise, committed during the Irish Civil War of the 1920's. I'm Irish, but it has nothing to do with me. My sole responsibility is in simply affirming that it happened, which I should, because it did. But I don't owe anyone an apology.
These people in the Baptist church owe no apologies except ones to the people that they've wronged or exploited, and I somehow doubt that includes any kind of slavery because they weren't the ones who enslaved anyone, and neither did their churches. They shouldn't be sorry and by the way, they're not- they're just trying to score some PR points because they're too timid to just say what everyone already knows and is also afraid to say:
That you're responsible for your own actions, and that when you try to link blame by linking someone to a group, especially in an inter-era context, everyone is fucked. My family tree is traced back hundreds upon hundreds of years. No slavery but I get lumped in with nazis and white nationalists because I'm white and I'm not foaming at the mouth about racism on social media. And here's the thing that will make people REALLY mad:
Even if I did have ancestors that took slaves, I still wouldn't owe anyone an apology for it. The people to whom I owe apologies are the people I've wronged.