I blog on WordPress as well and receive daily traffic from SEO alone. I think it's a matter of "diversifying", as they say, even though this is the world of blogging and not finance. I'd say there's so many platforms available, it'd be a shame not to use multiple ones, but it certainly doesn't mean we need to create panic and fear in people.

I think that as long as you have a solid strategy in place for your site/blog, you will definitely be fine and weather out updates and other changes.