While it's always interesting/practical ("just because") to have a full takeout sitting around locally, that would probably create a multiple GB tome (all of Gmail, Drive, ...) that would a day or two to generate and then potentially a while more to download, so for this experiment hitting "Deselect all" and then checking "Calendar" should be good enough.

The process of generating the takeout archive and downloading it are distinctly separate steps with some indeterminate amount of time in between, so you could very likely initiate the takeout from your phone, then follow up on the download link(s) it emails you when you get to a computer (IIRC the archive(s) hang around for a couple of days).

If you do indeed find deleted entries (nooo), I found that (a) Google Calendar itself has no auto-delete functionality (https://support.google.com/calendar/thread/3530801/how-do-i-...), but that if you have your calendar set up to sync with other software, that software might be issuing "deletion" requests (possibly under the guise of auto-cleanup...?) that is then getting synced back to Google Calendar (https://support.google.com/calendar/thread/8849196/my-calend..., https://www.makeuseof.com/events-deleted-automatically-googl...).