It this question and answer the same as my question?
I searched in the Help and up came 30 choices none of which included the word synchronize in the title. So I started digging. The "General" choice shows
Synchronize Ctrl+Alt+Y Detect all changed files and reload them from disk.
which is "in line" with the answer to the "linked question" I show above.
So my guess is that it is "file related" (it's in the File menu) so ... makes sense.