Sorry, that doesn't wash with this population. Those affected by this were either hired prior to 1990-something (when new employees were forced to join a DC not DB pension scheme) or were transferred into IBM by either a services TUPE or by having their previous employer bought by IBM.
For the first group, back in their day, I understand that IBM was a reasonably generous employer - although the pension scheme was never top-notch - and at the time IBM was still a significant market leader, particularly in research. IBM was then a good place to work - or so I was told. Of course, all this started to change following the changes to the company following its near collapse at the end of the 1990s decade!
The second catagory hardly had a choice about joining IBM. I know - I was one of them in the early 2000s. Your only choice was take it or leave (that is, be deemed to have resigned). In practice, many in my peer group talked loudly about leaving before the transfer but in reality I don't think that more than one or two actually did.
So, this wasn't in any way affected by people being willing to join either the IBM of 2009 or 2017.