It's not that B is now STRONG, it's just that you ought not to be using B at all. Long, long ago the internet was thought of as a visual medium and graphical browsers developed that all displayed the same set of HTML elements in essentially the same fashion. HTML 3.2 was an attempt to describe this set of elements. But that style of HTML doesn't work if the end user is blind or is simply using a non-graphical browser. HTML 4.01 was developed so that web pages would work on all browsers. HTML 4.01 is essentially a subset of HTML 3.2. Most everything related to presentation has been removed in favor of CSS. That some text is bold means nothing to someone using a Braille browser but strong emphisis will be presented somehow. The idea is the separation of content from presentation. You mark up the content so that it still makes sense without your presentation.
You can follow all officail changes, and even participate in the process, at the W3C.
“The power of the Web is in its universality. Access by everyone regardless of disability is an essential aspect.”
—Tim Berners-Lee, W3C Director and inventor of the World Wide Web