Its an interesting question. I'd say that it is very very likely that software will exist for our lifetimes that can read Canon's RAW file format. I am trying to think of any files that are obsoleted. At best, maybe companies that went out of business, Wordperfect, Lotus 123, etc. But, I even wonder if those files can be read somehow. Even through the various software updates, they are make backwards compatible so I can still open files from the mid-1990's.
Even if Canon suddenly went out of business or decided to stop supporting RAW, both of which I view as unlikely, existing software that can read RAW files still exists. The DPP version on my computer still works and other software makers would likely support RAW for as long as people were using cameras, so there would be a nice long transitional period. I would look at it similar to film or another older tech, you can still develop film, but it is less convenient than it once was.
That said, this is a good thought, but my archival efforts may be lacking. I think I do a good job of backing up with multiple hard drives, one located offsite, etc. But it is all electronic. It hasn't failed me. I can still open and view pictures/videos I took starting in 2003 (my first digital camera). But the most thought I have put into "archiving" is that I buy new external hard drives about every 2 years to keep those others from aging and so I am working off "fresh" backups from my original source.
Thinking about it, and I've done some of this, but I need to print more.