Agreed.
Technically users could go into the dev tools, find the rule, and uncheck the display none and then use the Discourse search.
But I seriously doubt many would. In fact I think if you used a less obvious selector that the owner would never become aware of it. eg.
div.panel ul.icons li:first-child {
display: none;
}
I don’t understand the request, IMHO Discourse search works great. I’m guessing the owner has been listening to some SEO snake oil.