Forum Discussion
Wiki in Modern Page format
Found this recent reply from Microsoft on their SharePoint UserVoice page:
We know wikis are critical to sharing knowledge within your organization! We’ve been slowly building capabilities to share information more easily with our focus on modern pages and web parts. And with that work, we’ve been adding some of the capabilities we hear you want when people refer to wikis (easily add links to other pages or content, add metadata to each page to help people find and categorize it, roll-up content based on that metadata to show groupings of like content, etc.) But we know this isn’t all that’s required to have a great wiki. Many people also want wiki linking syntax e.g. [[]], we don’t yet support that, but we do support ctrl/command + K from the text web part to search and find pages on your site. We’ll be working on adding wiki syntax shortly. We know you also need easy roll-up pages, maybe an index page, etc.
In short, we’re still working on what it will take to make a great wiki experience leveraging the building blocks of web parts and modern pages. If you have specific ideas about what you need/want, we’d love to hear them. Please add detailed comments to help us frame what you need for our MVP.
https://sharepoint.uservoice.com/forums/329214-sites-and-collaboration/suggestions/7915317-a-total-revamp-for-wikis
So sounds like the wiki functionality might be replaced by better modern pages and web parts.