News-icons-appear-one-bar-later

I'm not sure but this might've been done on purpose to avoid peeking in event providers - insider transactions in the first place. Such an event can take place after the market close. But I see no harm in making news appear on the event bar.

Fine, so please turn this one into a #BugReport or #FeatureRequest

Wouldn’t the harm be that the news is released after market close, making such a placement a peeking concern? If you must access them in this way you can always look one bar ahead in your strategy code.

QUOTE:
making such a placement a peeking concern?

I can't see a problem here.

Even if the news is released (say) one hour before markets open, and I am able to read and understand it, I can issue a MarketOnOpen order.

I think at least all news which appear before midnight should be attached to the bar of this day. To have things in correct chronical order.

QUOTE:
Wouldn’t the harm be that the news is released after market close, making such a placement a peeking concern?

Since EOD strategies are inherently run after market close themselves, I only see harm if the strategy that looks at such News events also uses the opening price of the bar for its decision making. Or am I mistaken?

No, if a news items is released at 6:00pm EST, then the market has already been closed for two hours, then any operations on that bar would be illegally peeking.

I checked SeekingAlpha's "News" feed and it marks each item with a timestamp, allowing WL to tell whether the item was released after market close.

Well, after all this is just a display issue.
News Items are stored in an independent "database".
So if news is used in a backtest it is always possible to check the news' timestamp and take appropriate action.