I think it's definitely a coincidence. While there's nothing wrong with being competitive like that, I doubt Mike knew when DT were going to release their single. But, even if Mike did, releasing his stuff the same day as something as huge as a DT single would be a pretty bad move. Mike has got to know that, even among his own diehards, something like new DT music still blows away any news from most of his current projects, except for MAYBE new Transatlantic music.
Case and point, before seeing this thread, I had no idea Mike was releasing anything. Now I do thanks to this thread, but it would have gone completely under my radar otherwise. That's no insult to Mike, it's just that new DT music really is that big a deal in the extended DT family.
So, short answer: yes, it's a coincidence, and if it's not, it's a baffling and self-destructive decision.