Yikes. I think the biggest news is that these data center bonds are getting investment grade. The reason for this is not because their prospects have improved [0] - the reason is because they need more investors to buy them. Pension plans who can only buy investment grade bonds may be enticed to buy these bonds. And this way these bonds will make their way in pension plans. When defaults will start happening on these bonds expect bailouts - because we need to bailout pension plans.

It is eerily similar to the mortgage crisis in 2007-2008. Low grade mortgage bonds were given AAA rating and there were too many of these which then caused the crisis.

[0] the article mentions how more Date Center recent bonds required a higher interest rate. This implies the risk increased (during the same time Feds lowered the rate), hence the prospects for Data Center bonds diminished.