This is Tom’s talk from WordCamp Europe: https://youtu.be/Y3y74POsDvc?t=10972

What Tom is exploring is pretty interesting indeed. However, I do really really really hope that porting Gutenberg to the front-end is doable from a performance point of view, since now it has to download a huge amount of JavaScript, just for adding comments! Last time I checked (version 6.0), the Gutenberg editor loads 4.2 mb of JS, and Tom’s site is loading 2.2 mb (I don’t know how much from that is due to Gutenberg, but I guess most of it, since his site is otherwise so clean).

Adding Gutenberg to the front-end can certainly make sense for sites which are already very heavy on JS and full of dynamic functionalities. But adding so much load for any typical WordPress site, i.e. for simple blogs, can easily become a disservice to the site: more functionality at the cost of speed (at least for first-time users) will, most likely, not be worth it.

Maybe Gutenberg could ship an extremely bare version of it (eg: no “+” signs, no de-registering blocks from the front-end, i.e. no need to load JS to remove JS, etc), and weigh no more than 300-500 kb? Then I would consider adding it to a simple site, but not before then.