You're basing this on the hypothetical. I'm looking at the two Macs side by side right now, and who's to say that this hypothetical 24 would be the same aspect ratio as the 27? Nobody, because it's entirely hypothetical, and I'm basing what I'm saying on the very literal pieces of metal, silicone, and glass sitting in front of me as I type this. Even if they were the same aspect ratio, who's to say that the bottom of the display wouldn't be slightly higher, bringing the height in line with the 27? Nobody, because as previous, it's entirely hypothetical.
We've effectively established that they wouldn't reintroduce the 24 while still producing a 21.5 and a 27 anyway, so the whole exercise is moot.
Moot? Then why make that post?
Sure, Apple could revive an iMac with a 16:10 aspect ratio, but what are the odds of reviving not only a retired display dimension, but also a retired aspect ratio? The last iMac Apple produced with a 16:10 aspect ratio was the mid-2009 20". Every iMac since (starting with the Late 2009 21.5" and 27" iMacs) has had a 16:9 aspect. So, while my statement, like all statements in a thread like this, is hypothetical... It's not like it's a flight of fancy to think that Apple will keep producing iMacs with a 16:9 aspect ratio.
As to basing your opinion on your very literal pieces of metal... I can also take the very literal pieces of metal that I have, and line them up side by side: An Early 2008 20" iMac with a 16:10 aspect, a Late 2013 21.5" iMac at 16:9, and a Late 2013 27" iMac at 16:9.
What do your 24" iMac and my 20" iMac have in common? Apple no longer sells either display size, and they're both old. If we were talking about cars... What's more likely: The 2017 Ford Taurus will closely resemble the 2006 Ford Taurus, or the 2017 Ford Taurus will closely resemble the 2016 Ford Taurus?
Now, before you say it... Yes, all of Apple's current laptops have 16:10 aspect ratios. And yes, it's completely possible that Apple could return to 16:10 for a hypothetical 24" iMac. If they did, one might also expect that Apple will move back to 16:10 for whatever other iMacs they build - we can't assume 21.5" and 27" are, like diamonds, forever.
But one thing is fairly consistent over Apple's history... Apple doesn't do retro. So whatever the case dimensions and materials for a hypothetical, all-new 24" display... the design will either be consistent with the current design aesthetic, or a new one.
While I'm sure that somewhere out on the web is a cogent explanation or rationalization for Apple selecting 16:9 for iMacs while sticking to 16:10 for the MacBooks, I'm just going to pull a hypothetical out of my hat... They wanted the proportions of the iMac standing in the living room/family room/den to more or less reflect the proportions of every HDTV on the market, perhaps to suggest that those iMacs are intended, in part, for viewing HD videos. The closer the case proportions would come to 4:3, the more the iMac would resemble a clunky, old standard-def TV, or that 17" VGA CRT in the basement that they won't accept in the municipal trash collections.
