On screens that are wide enough to support the sidebar, the toggle has been removed to ensure latest threads and other stats are easily prompted by default. This should only affect the homepage on appropriate displays, and yeah we made sure it'll respect all ignored threads/forums.
There's no reason to remove the toggle. I like it hidden so I don't get stressful shit thrown up at me on the front page so I could easily jump to my watched threads. Only one active thread being shown per board on the homepage is way easier to deal with than a bunch on the side on top of that. This is a very ridiculous choice, so it would be really handy to re-enable it on desktop. (I'm on a macbook, and that's the browser that's refusing to let me hide it.) Taking away options like this, especially with no announcement just gets really irritating since i remember a long while ago the option to ignore entire boards was removed in a similar situation, before it was readded due to some pushback.
Please, at least consider announcing or doing a heads up for changes like this in the future... I'd really like my option back, even if it's fine for the shown-display to be the default setting, some just want their screen less cluttered or to avoid stress. (since it shows newest threads, at least on my end, it doesn't really do much with showing ignored threads as they're brand new threads, unless they're from the ignored boards like Etectera in my case.)