People who use screen readers or refreshable braille displays may find page refreshes or time-outs confusing or disorientating as it is not always clear what is happening. Part of this confusion is due to the fact that changes are occurring with the page without the user having interacted with the page or triggered and change themselves.
* Warn users that a page will refresh or time-out. * Provide an on / off switch on pages that automatically refresh for those users that do not want it to refresh. * Combo-boxes that trigger page refreshes should not be used. For menus that use drop-down combo-boxes, provide a 'Go' button. * Server-side page refreshes should always be used rather than client-side page refreshes.
...metadata provides important contextual information for people navigating your site, especially those with screen readers who rely on things such as page titles, structured page headings, and lists.
Note: this is why 'keywords' especially should be few and explicit to the page. No general re-iteration of the dictionary or generic 'all my sites keywords on every page'. And why a good 'description' is valuable beyond directory or SE snippets.
Metadata (tags) have not lost relevance simply because one or more SEs discounts/ignores one or another.
Anything which automatically refreshes is really bad for someone using a screen reader because the screen reader will probably keep jumping back to the top of a page and starting over reading it. Apart from being incredibly annoying, it is actually really confusing, especially if you're just getting to know your screen reader and don't feel very confident with it.
If you're talking about redirecting to another page, it can be confusing as well unless you leave a long enough gap so that the user can hear that he's being redirected. The screen reader will start by reading the title bar. Depending on how the user prefers to navigate he can jump paragraph by paragraph or heading by heading or just have the page read in full. In any case, unless he has time to get to the point where he's told that he's about to be redirected he may get confused as he'll hear a title read, start to navigate and then hear another title read and won't know what's happened or how he got to the page he's on or what happened to the page he thought he was on.