I’d be open to integrating Zcash. I’m currently keeping an eye on coins we can/should integrate after launch, and it’ll come down to:
- Technical difficulty
- Economic sense
- Personal interest by developers and the community
I don’t image Zcash would be technically difficult. Despite discussing the shielded protocol, I have prior experience and the Serai codebase was designed to minimize requirements on external networks and be flexible around them
Regarding economics, the main question would be about ensuring liquidity.
Regarding community, I’ve had a few members of the Zcash community express interest 
Regarding developer interest, there are specific aspects to Zcash I can appreciate.
It’s definitely a possibility.