When it comes to the <meta> element acting as a pragma directive for page refresh, HTML spec says that
user agent may ... inform the user of any and all aspects of its operation, including the state of any timers, the destinations of any timed redirects, and so forth.
It also says that users may be allowed to cancel timed redirect. I suppose the two things are related, as the user should be notified of the imminent refresh, in order for him to decide if it must be stopped.
For what I know, at present no UAs allow users to stop meta refresh, even though for some of them there are "extensions" which state they can (and it's not true).
In addition to this, authors wishing to use other ways to refresh a web page (e.g. location.replace or AJAX) cannot use meta refresh as a fallback solution without recurring to <noscript>, which is an obsolete way of doing things (and not always possible).
I'd rather suggest a little change in the spec. There should be an interface control for pragma "refresh" directive, so that the refresh time can be retrieved and the action itself can be stopped. Or at the very least, the possibility to stop meta refresh by simply removing the <meta refresh> node (as a lot of authors used to ask whether it is possible or not). This would allow extensions to actually stop it (in addition to retrieving time and destination directly from the element itself). It would also allow authors to program a fallback refresh, working together with JS advanced solutions (a script could allow the user to choose a different time, or provide an update for specific parts of page content, while meta refresh could allow a basic non-scripted solution).