How do I determine which version of Halloween (1978) to buy on Apple TV?

No. There is more of a difference than than languages. Someone spotted a “new” version of Halloween (from Shout! studios) being released today in the “upcoming” titles in the movie store in addition to the version they already had. This isn’t an isolated incident. This happens often in the Apple movie store. Sometimes they’ll differentiate more than one version of a movie with the addendum “director’s cut” or “unrated version”, but a lot of times they don’t bother to list any substantive differences. You then have to got to Reddit and fan forums to figure out which is which. Kind of ridiculous actually.

No. There’s more to it than that. Someone spotted a new version of Halloeeen (and part 4 and 5) being released today in the Apple movie store from Shout! Studios, now we have to figure out which is which since Apple refuses to list more helpful info when people are trying to figure out which version of movie they want to buy. This happens quite often.

The pop-up on Apple's movie store of which versions of any movie they are SELLING should at minimum provide resolution, HDR or not, sound formats, runtime, distributor/license holder, and release year. At least then the customer could do some research to determine exactly what they're buying. The Shout! version is rumored to be HDR and remastered. Imagine being the team leader over this at Apple and being, "well, we won't even attempt to help our customer by locating and providing this minimal info and they can just gamble blindly with their money. Eeny, meeny, miny, moe". Nice.

Nope. First..."The main page for the movie provides all that".... That info is only relevant if it's a single version of a film, which this isn't. Wherever that got the info for the "old" version...they need to get that info for the "newly added" version as well. How hard can it be?

Second...You didn't scroll down far enough. The "buy button" or whatever its called clearly says "4k 2 versions". So which is correct? Who knows? So now not only do we NOT know what version of the film we're buying for our $15, we don't even know if its HD or 4K. Yay! Thanks Apple!

"Given the current date, I would say whatever you saw was an April Fool's joke by someone."

Wow. I had no idea Apple had no control over what was listed on THEIR MOVIE STORE. Must be Apple playing an April Fool's joke since they are the ones who who posted the pre-order date at THEIR MOVIE STORE for this "new" mystery version of this film for today's date and want their customer to gamble on what they're getting for their $15. Is it the same movie with subtitles? Additional languages? HD? 4K? Who knows? Just give us your money! APRIL FOOLS! Lol.

“I would say whatever you saw was an April Fool's joke by someone. There probably is no new version released by Shout! currently.”

Here’s the info at Cheapcharts that clearly states it’s a NEW Shout! release and 4K/HDR (not HD), but sadly their link takes you to the main page at Apple’s movie store, so you still don’t know which version of the movie to select!

Halloween

I think your issue is you're simply guessing without actual knowledge. That isn't helpful.