The specific problem of the 2008 financial crisis was that the banks were going out of their way to obfuscate the source of their CDOs so that, even when it was clear in 2007 that the subprime mortgage market was unraveling, you couldn't look at your instruments and figure out whether or not you were affected. The problem wasn't the CDO, it was the obfuscation. And as far as I'm aware, the current debt offerings aren't being obfuscated--if you want to avoid the data center debt because you think it's junk, just avoid the stuff being touted as data center debt.
yes, i specificly remember when Lehman went under the banks stopped trusting each other's ability to assess their own exposure. The banks stopped lending to other banks and that's when Paulson got on his knees (literally, i think there's a picture of him on his knees in front of Nancy Pelosi) asking congress for cash to guarantee loans. The side effects started squirting out everywhere i think even Mcdonald's was hours away from bankruptcy because the corporate paper market suddenly ceased to exist. Also, money market returns turned negative briefly, that's like a negative interest rate on a traditional savings account bad. It was bizarro world for maybe 72hrs.
The movies don't really do justice to just how upside down and nonsensical the financial world became. It was a knife's edge for 2 or 3 days.
My fear is that this is all going to turn into one big front-running exercise where those connected with the Trump crime family are warned to get out first, banks that swear allegiance are bailed out next, and the rest of us get to hold the bag.