There is a petition to upgrade microformats to v2 in the core. Instead of continuing to support microformats, which rely on CSS classes, they should be completely removed from the core as bloat. There are several reasons for this:
This is plugin and theme territory and is usually handled by either an SEO plugin, a dedicated schema plugin, and theme developers implement their own markup.
The markup is not interleaved with the user-visible text, which makes nested data items easier to express, such as the Country of a PostalAddress of a MusicVenue of an Event . Also, Google can read JSON-LD data when it is dynamically injected into the page’s contents, such as by JavaScript code or embedded widgets in your content management system.
Fewer things to support. What if microformats v3 comes out? Do we upgrade again? Google still supports microformats, but it is slowly removing support for older formats. Recently, they stopped supporting data-vocabulary*org. At some point, they will stop supporting microformats v1. This means we either need to upgrade it or, better, remove it and let plugins/theme handle it.
If removal is not an option, we should consider upgrading microformats to v2.
Possible implementation
Removal of microformats support from the core. There are a couple of options:
Introduce a filter to disable microformats in a minor version.
At some point, introduce a filter to enable microformats support (or core plugin) in a major version.
If we’re not worried about backward compatibility, it can be removed in a major version without filters. A core plugin would probably be a good idea just in case anyone needs it.
I think it’s part of the history of WP that the microformats grew out of codifying what was being used on sites all over the internet, hence v1 exists the way it is because it was in WP. I’m not sure, though, and it might be more of a chicken/egg kind of thing.
This is a really good point. We do need to think about minimising the future workload.