Theres some misinformation in this thread that could use some clarifications.
First off, cheats wasn't removed due to conflict. In fact the author of the branch has updated and rebased it several time and he still makes builds with it and uploads them to his own github. The problem with cheats is a fundamental issue with citra that would take hundred and hundreds of hours of research and work to make it work properly, and no one will step up to do it. Cheats often rely on the location of certain memory addresses to be consistent, and how things work on a 3ds console, they are consistent. The problem is citra does not emulate the memory at a precise enough level to make these cheats work. Because of this, there are many many cheats that are written for a 3ds that will not work in citra. Fixing this is a hefty amount of work, so its not likely to happen soon.
To be honest, its possible that we could have just merged it (I would have asked for/volunteered to do a rewrite of the GUI if it was going to get merged) and just lived with the fact that some cheats won't work, but several of the maintainers decided that its not going to happen. It'd end up being a maintenance nightmare down the road when people's cheats break all the sudden when citra changes. The final consensus was it would be much better to add this when citra is more stable.
Just because something is a useful feature doesn't mean its going to get merged. Theres plenty more to consider than just its usefulness Its a shame to me because turning down contributions like this usually means the contributor loses interest in the project, but theres really no other way to handle the situation... I can think of a few other rejected pull requests that the authors put tons of work into, and well, they just stopped contributing afterwards. But thats just the way open source development goes sometimes
So, in summary, cheats isn't coming back.