As far as I know, unless Quicken has made a change in a version a bit "newer" than mine, Corporate Name Change doesn't do what you're describing, it simply changes the name, along with a Reminder, with other values unchanged:
It's always worked in this fashion as far as I know. Are you sure you used Corporate Name Change here
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I suspect a misunderstanding of who does what. Rather than blaming Quicken, more likely your brokerage probably sent the remove and add transactions and failed to send the cost basis and lot info in that add shares data. That is a common ‘failure’. Quicken pretty much has to accept what the brokerage sends.
The brokerage sending the data as a new security may be quite valid especially if the CUSIP is different. The user is not obligated to accept that approach.
As a user, if I wanted to process this in my file as a name change, I would:
If you want the security names before and after to be different, an alternate corrective path is possible