Screenshot 1. When exported to PNG, Transparet Background is ticked.
Screenshot 2. When the PNG is placed, there is Use Transparency Information.
I see no difference with or without Use Transparency Information.
What is it for?
I happened to find out Use Transparency Information was sometimes on and othertimes off.
I tried to find out where the difference came from.
I arrived at the finding; Use Transparency Information is on, when exported to PNG with Transparent Background.
Then, I was curious what Use Transparency Information is for?
It's the motive of the question?
I made an original file with Id and exported it to PNG with Id.
That is odd.
You can export as PDF/X-4 snd place that in INDD. Which causes much better quality than this terrible PNG.
You can even place an INDD in INDD.
Use only a PNG if you do not have any other oportunity.
Yes, it seems to have no effect. I tried using bot 8-bit and 24-bit PNG files with transparency and the option made no difference to the placement of either file. They all show transparency. If a PNG has no transparency the option is unavailable. This looks like a bug. Is it a problem of just a discovery? If you want you can report it here.
It's just a discovery and curiosity.