This pretty much echoes what we know already, but the more fact you have. The better off you are I think.
This is a quote from HTC UK fb page, reply on a post.
..we’re delighted to confirm that HTC One (M7) users will be able to update their software to Sense 6 from the 21st May 2014. The update will be rolling out to HTC One (M7) handsets across Europe and will continue over the coming weeks. However, we cannot provide an exact country-by-country schedule.