Hello,
it shouldn't give any immediate technical problems, but there are some minor points you might want to consider:
<ul>
<li>With this rule, you are versioning every content in sites, not just documents in the document library (think about discussions, comments, events in calendar…)</li>
<li>With this rule, you are also versioning Surf-related artifacts put into a site (e.g. dashboard configurations, activate site page configuration) - depending on the volatility of the configuration and amount of sites, you can end up with a long version history, which you can't use directly</li>
<li>I am not sure about the rule applying to renditions / thumbnails, but my current inclination would be that these would also be versioned unless you specifically excluded them, and create additional but useless nodes in the database</li>
</ul>
Regards
Axel