1. Financial analysts were not devoting much time to analyzing the risks from rapid rate increases, as rapid rate increases were deemed very unlikely (in part because the Federal Reserve itself had offered guidance that it was unlikely!). Furthermore, the time that was spent on analysis of this low-probability event was spread very thin (interest rate increases affect pretty much everything), and the perception of “zero risk” in T bonds would have bumped them to the end of the list for analysis, meaning even less analysis time for this outcome. Just now on Twitter I’ve seen two financial analyses praised for their prescience in this event - one from the FDIC, one from Byrne Hobart. Both of them only picked this up after the rate increases came into effect.
2. Even if there was full awareness of this risk, and plenty of forewarning that the rapid rate increase was definitely coming, the regulations as written would still permit these investments. The bank itself would probably have made smarter decisions and wouldn’t have collapsed, but that would be orthogonal to the regulations under discussion in the OP. (In my initial comment I even sketched out the argument that the regulations would have been mildly opposed to the smarter decisions.)