Our suggestion is still to wait, as I said in my post on Yoast.com on WordPress 5.0. Yoast SEO is awesome with Gutenberg and I can't wait for everyone to try it, but if you're going to try it now, you might think that it's annoying and slow. If you use it with Gutenberg 4.7 (currently in RC phase, you can get it here), it's already much much better. This means that if you update in January, you should certainly be OK.