The HDMI forum has discouraged vendors from specifying which HDMI spec revision a product supports. This is because many features can be supported even on previous revisions, while other features are not ready or not available for implementation.
Features available now include things like eARC, VRR, high refresh rates, and such. Features that won't be out for a while (think 2020) include high bandwidth like 48Gpbs (in fact, the qualification tests are not complete yet so no one can release any product for certification).
If you want to wait for 8k support and all that, you'll have to wait until next year. Likely certification standards will be approved later this year while approved cabling and switching devices will start appearing next year as the devices get certified against the tests.