You can make Linear projects and issues public for your users to vote or give feedback on. Take votes as a “smoke signal”, that there is some problem this feature could solve, but not necessarily everything that gets a lot of votes should be built.
You can only publish only Linear issues and projects, nothing else. That way, your users know that everything on there is really visible for engineers and can be acted upon.
Every new project you create in Linear, will automatically appear in the “Pending projects” section, from where you can decide to hide or publish it on your portal.
You can also publish issues on your roadmap, by opening Linear and giving the label “Productlane roadmap” to an issue (Press L when hovering on an issue). After that, it will automatically appear on your roadmap.