The "trending" calculations are realised via hivemind.
The trending posts are fetched from the condenser with bridge.get_ranked_posts and the parameter sort=trending.

A new sort category could add without a hardfork. But a new category would be required. This would have to be changed in the Condenser and in Hivemind.
In my opinion, it would be "simpler" to exclude the posts with votes from various known bots from the trending calculation. The only difficulty here would be defining the conditions for this.
Which accounts? Which vote value?

The code is public anyway and the bot list could become a transparent part of the Hivemind code.

I am currently working on another new function for the Condenser in Hivemind.
If we can clarify the open questions about the trending, an implementation would be quite conceivable.