Is it necessary to upgrade the version of CoreData in iOS after modifying the data?

I have tried the CoreData modification operation in Demo as follows:
1, first create a new basic table and add fields, then add some data in app
2, exit app, new table, add new fields, add Relationships
3, and there is no flicker after rerunning the program, and all the previously added data can be queried

.

but all online posts one-sidedly mention that if you want to modify coredata (including new tables and fields), you need to add a new version. But this is obviously contrary to the conclusion that I am operating now. I would like to ask the forum god, why did my operation not collapse?

Feb.27,2021
MySQL Query : SELECT * FROM `codeshelper`.`v9_news` WHERE status=99 AND catid='6' ORDER BY rand() LIMIT 5
MySQL Error : Disk full (/tmp/#sql-temptable-64f5-1b34f0e-2bf61.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
MySQL Errno : 1021
Message : Disk full (/tmp/#sql-temptable-64f5-1b34f0e-2bf61.MAI); waiting for someone to free some space... (errno: 28 "No space left on device")
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