Getting to the forums from the home page is the same as it was last week and for quite some time. it has always required using a link. If you simply click FORUM it will take you there.
Or, you can simply bookmark the forum main page and skip the home page altogether if that helps you.
This is true as an independent statement, but not really a response to my point earlier. The link (now gone, it seems) to your most recently active thread was a way to, in a single click, go directly to a forum (and thread) that interests you.
By forcing organic navigation through the hierarchy each time, it adds several steps to an operation that, I suspect (and you probably already know, from looking at usage paths and logs) is a frequently-executed operation by visitors. I'm not sure that's helpful from a UX perspective - unless your analysis of the logs and usage show that most people are already drilling down every time from the home to the forums list to the forums sublist to the forum itself. In that case, my use of the functionality may just be an outlier.