The problem we have with 6th edition is how much of a mess it is. There are many things that are imbalanced and in order to try and balance things They release untold expansion books, stronghold, escalation, dataslates, New armies as allies (Lords of War, Inquisition, Imperial Knights) - Whilst the 6th edition rulebook doesn't refer to them at all, many people have been dubious about buying and using them. In order for GW to be able to continue to rip people off make profit from such releases, they are indeed creating a new edition to cater for the wave of recent releases (and upcoming releases)
Whilst they make no mention of calling it '7th' edition, they do continue to call it the 'New' edition and do not mention it is just a 'revised' edition.
With rumours of massive changes in some areas, (Psychic phase - Changes to snapshots in overwatch, to name a couple) it does appear this edition will work somewhat differently to the previous edition. 6th edition wasn't great, but nobody called for it fixing this early. It feels like this is all designed to make as much profit from their miniatures while they can.
Regardless, I am trying to view it through rose tinted glasses. It's happening and there's nothing anyone can do about it, so I'm looking forward to learning about the changes and adapting my style of play. I am hoping that this new edition will give me more reason to bring out my Chaos Space Marines (as, at the moment, they just can't seem to win anything)