This is the message they put in for people using older versions of Quicken because of the FDS to FDP back-end conversion. That is obviously only an issue for people who have a current subscription and would lose online account connectivity if they weren't using a relatively current version of Quicken (in the case of Quicken Mac, version 6.4 or higher).
I suspect that the Quicken folks implemented a simple check upon the program launching to display the warning if the application is < v6.4. The more precise way of doing this would have first checked to see if the user had a current subscription, and then if the application was < v6.4.
But because they didn't check subscription status, it means that everyone with software older than v6.4 is seeing this notice — even though it's irrelevant for users who already have lost access to connected services because they have a lapsed subscription or older pre-subscription version. Quicken subscription began with version 5.0 on Quicken Mac. Quicken 2017 was version 4.x. I also launched old copies of Quicken 2016 (3.x) and Quicken 2015 (2.x), and they also open with the same message. It's clear that anyone launching Quicken Mac prior to versions 6.4 gets this message every time the program is launched. And as you can see, there is no "Do not show again", "Remind me later" or similar checkbox.
As I wrote above, I don't know if they simply took the easy route of popping the message for anyone launching Quicken Mac who doesn't have the current (or near-current) version and didn't think about the fact that there are people using older versions of the software who are not affected by the FDS > FDP change for whom this message is irrelevant. Or perhaps they decided it was a way they could nudge (read: "annoy") some people using old versions to upgrade to a current subscription version.