Given that the "sandbox era", as you so quaintly name it, is considerable MORE "historical" in every way that matters than the deterministic event system that preceded it in EU2, no, I do not read that into Paradox' announcements at all.So, EU4 has been announced and Paradox said (Strategy Informer interview) that they'll focus more on historical material. Thus, EU4 will feature thousands of historical events and monarchs...
How does the Old Guard feel ? Do you think the sandbox era is coming to an end ?
This is the interpretation of "historical" as meaning: Give it a historical setup at start and let, to the best approximation given the level of abstraction, historical factors affect gameplay afterwards.
I read it as "even more context-sensitive random events that mimic events from our recorded history" and "more complex context-sensitive event chains" and "more context-sensitive country-specific flavour events". I read it as "more historical ways of handling country relations". There are many ways to read it, but there's no way I can read it that suggests ending the "sandbox era".
Which strongly suggests that one can read just about everything one wants into the statement, depending on what one considers to be historical.