I think I see where you're coming from with that reading of the wiki.

Here's how I think about this: given infinite time and patience, I'd mark individual traffic signals at every single intersection aligned with the stop bars. But since I have finite time and patience, the single signal at the junction does the job in most cases. There is basically never a signal right in the center of the intersection in the real world, so it's more accurate to tag where each signal impacts each way, but placing one signal in the center is a sometimes-necessary compromise to save time.

I don't think there are any routing concerns in cases like this - all the signals only apply directionally, so a driver would only be affected by one signal no matter which direction they go. By tagging each way, you're just breaking up the single signal into four (or more, depending on the intersection) pieces, but the cumulative effect on routing (and the total number of icon "effect cones") remains the same.

Essentially, I think reverting the change would make the map less accurate, but I'm not going to get into an edit war over it.

I marked the stop bar locations for each incoming way according to the "Tag all incoming ways" section of the highway=traffic_signals wiki article (highway=traffic_signals). Just trying to clarify it a bit since it's a busy intersection with a wonky shape