Generally the forum is for asking questions, sharing ideas, etc. People talk about things here, ask for help, report bugs with dev builds, etc. We don’t, however, use it as a repository for bug reports or feature requests. Those should be filed at https://github.com/SublimeTextIssues/Core/issues.
Just because a single post was made seven years ago on the forum does not mean the development team even saw the request.
In terms of planning, we do not generally commit to timelines for specific features. The development of Sublime Text and Sublime Merge follow a curated vision directed by Jon, and informed by performance and practical usability. Sometimes features are not implemented because they don’t fit into the current vision of what we see the software being, other times we won’t implement features because the implementation cost would be far too high for the benefit, or there are somewhat reasonable workarounds. We won’t be everything to everyone. The editor and IDE landscape is diverse with many users looking for different things, and many products filling different use cases.
In terms of your specific request, I don’t think there is a reason we wouldn’t ever implement character spacing, but more likely we’ve just seen very few requests for it.