I came across your post on [topic] that you’ve published back in [year]: [link]
The content was well put together, though some of the ideas and information in it are already outdated. Just thought of asking if you have any plans of updating this content?
By the way, my name is [name], and I work with [brand], where we’ve written dozens of practical guides about [topic].
I know you have a lot on your plate, but I was just thinking that perhaps I can write the updated version for you instead.
Let me know if you’d be interested in collaborating on a [year] version of the [topic]. I would love to help in any way possible.
PS: What’s in it for me? Just want the exposure as a co-author for one of your blog posts. :-)