mysqldump between servers with different timezones (tz-utc)
That sounds like the "proper" way.

A TIMESTAMP column contains the time in UTC, but converts when storing and fetching, so that you can only see the value converted to your local time.

A DATETIME column, on the other hand, is like taking a picture of a clock.  There is no TZ conversion during store/fetch.

Since mysqldump is essentially a bunch of SELECTs, and the reload is a bunch of INSERTs, the data in the file looks like a picture of a clock.  By using UTC during the fetch, the file will contain UTC time.  By having that SET, the INSERT will, again, do no conversion to mess up the value.