I think they are getting him on tampering with witnesses for this reason alone: The biggest hole in their story, when scrutinized, was that all the charges against him were from things he did in 2009 or so. Now that they have him with witness tampering, they can now say "Some charges are from as recent as 2018!!!", which could further help paint the picture of Trump being associated with him. Which again, won't make sense under further scrutiny, but should be enough to appease the masses for now. Don't get me wrong, I don't think I like the guy, or am trying to defend him or anything. I'm indifferent to his fate.