"As someone who worked in an Intel Validation group for SOCs until mid-2014 or so I can tell you, yes, you will see more CPU bugs from Intel than you have in the past from the post-FDIV-bug era until recently."
I think Intel was more concerned about the time it took to make a new CPU rather than the cost. At least that was my impression of it at the time.
That testing is a cost is a given. But it's a known cost compared to what a huge batch of faulty CPU's can cost. Or how about a ruined reputation, how do you even know what that could cost you?
I suppose Intel already use a lot of automated testing, but given all the bugs since the change it seems it is not enough.
Did they really intend to just "skip" validation or did they try to automate it further, to decrease time to produce a new chip?