I have an answer to the question I posed in the .140 thread (now locked) regarding this change introduced in that build:
NEW: Reworked how 'Recently Imported' and 'Recently Ripped' are pruned at shutdown -- always keeps things 7 days old or newer, keeps last 50 items (breaks on album boundaries), removes entire playlist after nothing new for 30 days. (Options > General > Advanced > Clear 'Recently Imported' playlist skips this logic and deletes the playlists on shutdown)
I can confirm that Recently Ripped (and presumably Recently Imported) gets cleared by MC per the new "features", automatically, apparently with no way to prevent this action. That's a huge change from how MC has worked for many years/versions, and seems regressive at best, harmful at worst. MC doesn't know how a particular user works with the Recently... lists, so MC can't know how to "help" the user manage these lists.
My evidence: Using MC .132, on March 13 I ripped two CDs, 43 tracks total, and didn't have time to review and tag before going out of town. On March 20, the list was as I left it. I ripped two more CDs, for a total of 4 CDs and 60 tracks in Recently Ripped. This morning I upgraded to .143, restarted MC, and the oldest of the CDs (the one ripped earlier on March 13) is now gone from Recently Ripped, which now lists 3 CDs, total of 51 tracks. I presume this is the result of MC (almost) enforcing the new rule "last 50 items (breaks on album boundaries)".
Note that I always uncheck "Clear Recently Imported playlist on exit", and it remains unchecked in .143. In the past, this prevented MC from doing anything to the Recently... lists, leaving it to me. Isn't a core value of MC that it gives users the power to manage their media data as they wish?
Yes, I know which CD disappeared, and I can use Album view or similar to go to it and finish my project. And yes, I know of many ways I could have separately saved my Recently Ripped list in anticipation of MC's purge. But devising workarounds is not the issue.
Questions for anyone who knows:
Why was this change made; is there a rampant problem with too many tracks accumulating in the Recently... list (dragging down performance, perhaps), and/or strong user demand that MC "fix" this?
Assuming there's a good reason to automatically purge the Recently... lists FOR SOME USERS, why can't this behavior be user-controlled so optionally MC can be told to do nothing, just like pre-13.0.140 worked. Allow the user to retain total control and be responsible for clearing these lists, just like the user is responsible for not having other abandoned playlists dragging down performance. Leave this "override" as an Advanced option, for users who (a) can be responsible for their own database and (b) don't want MC to discard long-standing functionality.
Please!