This is certainly still on the radar, yes. Note though that almost certainly we will go for the option where archiving will not make things show up in search (unless you explicitly opt-in to include it). The main purpose of the archive would be declutter both the sourcelist as well as search lists, removing projects that are not relevant anymore, whilst still preserving your old notes and projects in case they ever become relevant again.
If you just want projects to some place to declutter the sidebar, but still want to search them, I would suggest you simply create an Archive category and move your projects there, then collapse that category to not take up any space. Same thing if you see the archive as some way to mark a project as completed.
This is true for all features so far, that’s indeed always the goal.