Sounds good to me. I have had very little time for FluidSynth or my other free software projects and I haven't heard much from other maintainers as of late, so it seems to make sense to make things easier for collaboration and contribution.
That's great, thanks for being so open to this request! I would love to take a more active role in the future FluidSynth development, but mostly as contributer and possibly reviewer of patches, not as a maintainer. Having the project on GitHub and maybe a core team and/or maintainer with more time on their hands would be fantastic.
You, the rest of the core team and other contributers have provided us with a superb software synthesizer! And it looks to me like you have kept the project very much on track with the initial goals. In my opinion, that is one of the most important jobs of a new maintainer or core team (much more important than reacting to patches or bug reports): deciding on the direction the project should move towards, keeping the project focused. And maybe put a few guidelines in place that make shared coding more enjoyable, like a defined coding style, for example.
All the best,