I can confirm this.
Searching for "tall windscreen for klr 650" using the Forums Lens gives nothing but Reddit results. One would expect results from a forum like https://advrider.com/f/ first and foremost. ADV Rider is a motorcycle forum with hundreds of thousands of members and millions of threads.
If I 'lower' Reddit from the results, I still get Reddit.
If I 'block' Reddit from results. I get nothing.
Searching for "best thermal paste" with Reddit blocked:
With the Forums Lens off for this query, I do get a forum as the second result and plenty of other forums:
I might even posit that by using a special Lens for forum results, one might actually want to not surface results from Reddit which dominate search results normally. I go out of my way to avoid Reddit and have actually lowered it in my general search.