I noticed this immediately because I use kanshi (highly recommended for laptops running sway!). I don't know the how or why (maybe it's the wlroots bump), but when I upgraded Sway to 1.9 today, the Hex ID form one of my external monitors changed. So I had to update it in the config for kanshi to work again.

Just a heads up for other kanshi users, and people whose scripts may be influenced by this.