Nice one, thank you cheeky.
Just put on my new(ish) Roku an it turns out it updated 9 days ago. Oddly that blog post is dated in September, but all the articles complaining it broke something seem to have come in the last few days. I wonder if they wrote it a while back but only made the post "live" when the update launched. Or the more obvious reason, that they've been rolling it out for a while now and it's only some older models that have a problem with it.
Just found this as I was composing this.
I looked into the Live Channels a bit more and it doesn't seem available to me. Reading between lines, I get the impression it's only available in US at the moment.
Ah. It looks like Live TV Channel Guide has been available inside the Roku Channel app since June 2020 in US. See here https://www.roku.com/blog/live-tv-channel-guide
So this probably means they've expanded the functionality in Roku OS 10.5 so that you can see the channels outside of the Roku Channel app on the Home screen that you first see when you start-up your Roku. That certainly sounds worthwhile, I hope this becomes available in other countries.