Does the platform support spin text or email content rotation?

You can use it via two following ways.

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Hey [RANDOM_CONTENT:there|you|buddy],
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Or in the combination of the above-mentioned default tag as follows.

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Hey [FNAME:filter:defaultvalue([RANDOM_CONTENT:there|you|buddy])],
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Result:

If there is a first name populated in the data, then it will appear as:

Hey David,

If there is not a first name populated in the data, then it will appear as following randomly:

Hello there,

or

Hey you,

or

Hey buddy,