RAC website advises that cars built from 2011 are compatible. But they also advise to avoid E10 on cars built prior to 2002 as problems have been reported. It looks as if in the short term E5 will still be available in some places, but I guess it will be like the unleaded debacle...more expensive, difficult to find and fading away after a few short years.
Although it may not damage engines, it’s the ancillaries like fuel pipes etc that will rot away. They also say it doesn’t store so well so I guess those who only polish rather than drive could find themselves in trouble.